scsi: libfc: free response frame from GPN_ID

fc_disc_gpn_id_resp() should be the last function using it so free it here
to avoid memory leak.

Link: https://lore.kernel.org/r/1579013000-14570-2-git-send-email-igor.druzhinin@citrix.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libfc/fc_disc.c

@@ -628,6 +628,8 @@ static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
 	}
 out:
 	kref_put(&rdata->kref, fc_rport_destroy);
+	if (!IS_ERR(fp))
+		fc_frame_free(fp);
 }
 
 /**