fixed a warning

src/realm/util/file.hpp

@@ -660,7 +660,7 @@ class File {
         AccessMode m_access_mode = access_ReadOnly;
         std::string m_path = "gylle";
 
-        MapBase() noexcept = default;
+        MapBase() = default;
         ~MapBase() noexcept;
 
         // Disable copying. Copying an opened MapBase will create a scenario
@@ -749,7 +749,7 @@ class File::Map : private MapBase {
         m_reservation_size = other.m_reservation_size;
         m_offset = other.m_offset;
         m_fd = other.m_fd;
-        m_path = std::move(other.m_path);
+        m_path = other.m_path;
         other.m_offset = 0;
         other.m_addr = nullptr;
         other.m_size = other.m_reservation_size = 0;

src/realm/util/file_mapper.cpp

@@ -248,7 +248,7 @@ static std::string dump_logged_mappings()
         else
             stream << "    --M" << std::endl;
     }
-    message = std::move(stream.str());
+    message = stream.str();
     auto logger = Logger::get_default_logger();
     logger->fatal(message.data());
     return message;
@@ -602,6 +602,7 @@ void* mmap(const FileAttributes& file, size_t size, size_t offset)
                 prot = PROT_READ;
                 break;
             case File::access_None:
+            default:
                 prot = PROT_NONE;
                 break;
         }