Update ci macro path

Summary:
The macros have moved from `fbcode/` to `tools/`. See
https://fb.workplace.com/groups/1243087773044302/posts/1477603662926044

Reviewed By: dtolnay

Differential Revision: D67821059

fbshipit-source-id: 1aed279429f62548065320016c64b2148baf06e2

btd/src/diff.rs

@@ -1265,7 +1265,7 @@ mod tests {
                 ..BuckTarget::testing(
                     "ci_hint@baz",
                     "foo//bar",
-                    "fbcode//target_determinator/macros/rules/ci_hint.bzl:ci_hint",
+                    "fbsource//tools/target_determinator/macros/rules/ci_hint.bzl:ci_hint",
                 )
             }),
             TargetsEntry::Target(BuckTarget {