fixed clang compiler warnings

git-svn-id: https://vsmartcard.svn.sourceforge.net/svnroot/vsmartcard@779 96b47cad-a561-4643-ad3b-153ac7d7599c

pcsc-relay/src/pcsc-relay.c

@@ -212,7 +212,7 @@ err:
     cleanup();
 
     if (r != SCARD_S_SUCCESS) {
-        RELAY_ERROR(stringify_error(r));
+        RELAY_ERROR("%s\n", stringify_error(r));
         exit(1);
     }