ocfs2: o2net: silence uninitialized variable warning

ocfs2: o2net: silence uninitialized variable warning

Smatch complains that, if o2net_tx_can_proceed() returns false, then "sc"
and "ret" are uninialized or maybe we are re-using the data from previous
iteration.  I do not know if we can hit this bug in real life but checking
the return value is harmless and we may as well silence the static checker
warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>