libglusterfs: Fix error handling in _gf_log.
libglusterfs: Fix error handling in _gf_log.

Unlock the mutex when an error occurs instead of jumping
straight to "out".

Signed-off-by: Vikas Gorur <vikas@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 394 (Possible deadlock in _gf_log)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=394

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster