For now: treat GCC 4.6 'unused-but-set' reports as just warnings (i.e., when -Werror).

For now: treat GCC 4.6 'unused-but-set' reports as just warnings (i.e., when -Werror).

GCC 4.6 has added 'unused but set' reports so this change allows builds to proceed without
erroring out for those building from SVN with GCC 4.6.

(AFAIK Wireshark source distributions do not enable -Werror).

This change can be removed (at least globally) once the code as been fixed.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@38311 f5534014-38df-0310-8fa8-9805f1628bb7