netlabel: remove unused param from audit_log_format()

Commit d3b990b7 ("netlabel: fix problems with mapping removal")
added a check to return an error if ret_val != 0, before ret_val is
later used in a log message. Now it will unconditionally print "...
res=1". So just drop the check.

Addresses-Coverity: ("Dead code")
Fixes: d3b990b7

 ("netlabel: fix problems with mapping removal")
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>