drivers/net/stmmac: seq_file fix memory leak

Use single_release() instead of seq_release() to free memory allocated
by single_open().
Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1640,7 +1640,7 @@ static const struct file_operations stmmac_rings_status_fops = {
 	.open = stmmac_sysfs_ring_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = seq_release,
+	.release = single_release,
 };
 
 static int stmmac_sysfs_dma_cap_read(struct seq_file *seq, void *v)
@@ -1712,7 +1712,7 @@ static const struct file_operations stmmac_dma_cap_fops = {
 	.open = stmmac_sysfs_dma_cap_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = seq_release,
+	.release = single_release,
 };
 
 static int stmmac_init_fs(struct net_device *dev)