Fix unused variable warning in ocs_cam.c
With clang 15, the following -Werror warning is produced:
sys/dev/ocs_fc/ocs_cam.c:2556:11: error: variable 'count' set but not used [-Werror,-Wunused-but-set-variable] uint32_t count; ^
The 'count' variable seems to be a left-over from some debugging code
that no longer exists, and can be removed without any functional change.
MFC after: 3 days