cmake: correct the link stanza for CoreFoundation

LIBRARIES is the (absolute?) path to the library.
LDFLAGS is the full linker stanza to correctly link with this lib.

By passing LIBRARIES as LIBGIT_LIBS, the linker ends up with the
absolute path for the SDK'ed version of CoreFoundation (which doesn't
exist), instead of the familiar `-framework CoreFoundation`.

cmake/Modules/SelectHTTPSBackend.cmake

@@ -49,7 +49,7 @@ IF(HTTPS_BACKEND)
 
 		SET(GIT_SECURE_TRANSPORT 1)
 		LIST(APPEND LIBGIT2_SYSTEM_INCLUDES ${SECURITY_INCLUDE_DIR})
-		LIST(APPEND LIBGIT2_LIBS ${COREFOUNDATION_LIBRARIES} ${SECURITY_LIBRARIES})
+		LIST(APPEND LIBGIT2_LIBS ${COREFOUNDATION_LDFLAGS} ${SECURITY_LDFLAGS})
 		LIST(APPEND LIBGIT2_PC_LIBS ${COREFOUNDATION_LDFLAGS} ${SECURITY_LDFLAGS})
 	ELSEIF (HTTPS_BACKEND STREQUAL "OpenSSL")
 		IF (NOT OPENSSL_FOUND)