Fix double conversion due to aws-lc/boringssl API

[haproxyFred]

This previous patch fixes some warning where several sk_509*() functions return a size_t (awl-lc/boringSSL API) in place of an int (OpenSSL API): 3cd3932

But this introduced others warnings where a double conversions were done into x509vfy.c where a "typedef size_t x509_siz_t" is implemented to fix the same API issue. This is correct but leads after the mentioned commit to such double conversion:
x509_size_t num = sk_X509_CRL_num(crls) ->
size_t num = (int)sk_X509_CRL_num(crls)

This does not please to the compiler ;-)

This simple patch fixes these warnings:

../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreFindCert_ex': ../../../src/openssl/x509vfy.c:218:20: warning: comparison of integer expressions of different signedness: 'x509_size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
218 | for(ii = 0; ii < sk_X509_num(ctx->untrusted); ++ii) {
| ^
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreFindCertByValue':
../../../src/openssl/x509vfy.c:265:20: warning: comparison of integer expressions of different signedness: 'x509_size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
265 | for(ii = 0; ii < sk_X509_num(ctx->untrusted); ++ii) {
| ^
In file included from ../../../src/openssl/x509vfy.c:37:
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreVerifyAndCopyCrls':
../../../src/openssl/openssl_compat.h:66:26: warning: conversion to 'x509_size_t' {aka 'long unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
66 | #define sk_X509_CRL_num (int)sk_X509_CRL_num
| ^
../../../src/openssl/x509vfy.c:358:11: note: in expansion of macro 'sk_X509_CRL_num'
358 | num = sk_X509_CRL_num(crls);
| ^~~~~~~~~~~~~~~
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreFindBestCrl':
../../../src/openssl/openssl_compat.h:66:26: warning: conversion to 'x509_size_t' {aka 'long unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
66 | #define sk_X509_CRL_num (int)sk_X509_CRL_num
| ^
../../../src/openssl/x509vfy.c:506:11: note: in expansion of macro 'sk_X509_CRL_num'
506 | num = sk_X509_CRL_num(crls);
| ^~~~~~~~~~~~~~~
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreVerifyCertsAgainstCrls':
../../../src/openssl/openssl_compat.h:65:26: warning: conversion to 'x509_size_t' {aka 'long unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
65 | #define sk_X509_num (int)sk_X509_num
| ^
../../../src/openssl/x509vfy.c:633:17: note: in expansion of macro 'sk_X509_num'
633 | num_certs = sk_X509_num(chain);
| ^~~~~~~~~~~
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreVerify':
../../../src/openssl/openssl_compat.h:65:26: warning: conversion to 'x509_size_t' {aka 'long unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
65 | #define sk_X509_num (int)sk_X509_num
| ^
../../../src/openssl/x509vfy.c:862:11: note: in expansion of macro 'sk_X509_num'
862 | num = sk_X509_num(certs);
| ^~~~~~~~~~~
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509StoreCombineCerts':
../../../src/openssl/openssl_compat.h:65:26: warning: conversion to 'x509_size_t' {aka 'long unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
65 | #define sk_X509_num (int)sk_X509_num
| ^
../../../src/openssl/x509vfy.c:1703:15: note: in expansion of macro 'sk_X509_num'
1703 | num = sk_X509_num(certs2);
| ^~~~~~~~~~~
In file included from ../../../src/openssl/x509vfy.c:15:
../../../src/openssl/x509vfy.c:1707:38: warning: conversion to 'x509_size_t' {aka 'long unsigned int'} from 'int' may change the sign of the result [-Wsign-conversion]
1707 | "size=%d", (int)(num + sk_X509_num(res)));
| ^
../../../src/openssl/globals.h:74:22: note: in definition of macro '__xmlSecOpenSSLError2'
74 | (param),
| ^~~~~
../../../src/openssl/x509vfy.c:1706:13: note: in expansion of macro 'xmlSecOpenSSLError2'
1706 | xmlSecOpenSSLError2("sk_X509_reserve(res)", NULL,
| ^~~~~~~~~~~~~~~~~~~
../../../src/openssl/x509vfy.c: In function 'xmlSecOpenSSLX509FindChildCert':
../../../src/openssl/x509vfy.c:1746:20: warning: comparison of integer expressions of different signedness: 'x509_size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
1746 | for(ii = 0; ii < sk_X509_num(chain); ++ii) {

[lsh123]

See better way to fix these in PR #894 and PR #895