scsi: fnic: Remove redundant NULL check

Fix the following warning reported by coccicheck:

drivers/scsi/fnic/fnic_debugfs.c:90:2-7: WARNING: NULL check before some freeing functions is not needed.

Link: https://lore.kernel.org/r/1647309219-12772-1-git-send-email-baihaowen@meizu.comSigned-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/fnic/fnic_debugfs.c

@@ -86,8 +86,7 @@ void fnic_debugfs_terminate(void)
 	debugfs_remove(fnic_trace_debugfs_root);
 	fnic_trace_debugfs_root = NULL;
 
-	if (fc_trc_flag)
-		vfree(fc_trc_flag);
+	vfree(fc_trc_flag);
 }
 
 /*