fsl/fman: fix a leak in tgec_free()

We set "tgec->cfg" to NULL before passing it to kfree().  There is no
need to set it to NULL at all.  Let's just delete it.

Fixes: 57ba4c9b56d8 ("fsl/fman: Add FMan MAC support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fman/fman_tgec.c

@@ -722,9 +722,6 @@ int tgec_free(struct fman_mac *tgec)
 {
 	free_init_resources(tgec);
 
-	if (tgec->cfg)
-		tgec->cfg = NULL;
-
 	kfree(tgec->cfg);
 	kfree(tgec);