storage/posix: Initialize op_errno to 0 in posix_create.
storage/posix: Initialize op_errno to 0 in posix_create.

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

BUG: 309 (In replicate set-up when exnihilate.sh is run , client crashes.)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=309

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster