sky2: Remove redundant NULL check for debugfs_create_dir

Since debugfs_create_dir() returns ERR_PTR, IS_ERR() is enough to
check whether the directory is successfully created. So remove the
redundant NULL check.

Signed-off-by: Ruan Jinjie <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Ruan Jinjie

drivers/net/ethernet/marvell/sky2.c

@@ -4528,7 +4528,7 @@ static __init void sky2_debug_init(void)
 	struct dentry *ent;
 
 	ent = debugfs_create_dir("sky2", NULL);
-	if (!ent || IS_ERR(ent))
+	if (IS_ERR(ent))
 		return;
 
 	sky2_debug = ent;