Silence warning from clang

Silence warning from clang

../../corelib/tools/qlocale_mac.mm:78:13: warning: '&&' within '||'
      [-Wlogical-op-parentheses]
  ...&& !qt_splitLocaleName(QString::fromLocal8Bit(result), lang, script, cntry)...
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../corelib/tools/qlocale_mac.mm:78:13: note: place parentheses around the
      '&&' expression to silence this warning
            && !qt_splitLocaleName(QString::fromLocal8Bit(result), ...
            ^

Change-Id: I64f745e7dfa64f28f264667372ed64f9e34ca3b7
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Reviewed-by: Thiago Macieira (Intel) <thiago.macieira@intel.com>