net: dsa: mv88e6xxx: Use kcalloc()

Use kcalloc() instead of hand writing it. This is less verbose.

Also move the initialization of 'count' to save some LoC.

On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
18652 5920 64 24636 603c drivers/net/dsa/mv88e6xxx/devlink.o

After:
=====
text data bss dec hex filename
18498 5920 64 24482 5fa2 drivers/net/dsa/mv88e6xxx/devlink.o

Signed-off-by: Christophe JAILLET <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Link: https://patch.msgid.link/2f4fca4ff8[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/dsa/mv88e6xxx/devlink.c

···
 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 	struct mv88e6xxx_devlink_atu_entry *table;
 	struct mv88e6xxx_chip *chip = ds->priv;
-	int fid = -1, err = 0, count;
+	int fid = -1, err = 0, count = 0;
 
-	table = kmalloc_array(mv88e6xxx_num_databases(chip),
-			      sizeof(struct mv88e6xxx_devlink_atu_entry),
-			      GFP_KERNEL);
+	table = kcalloc(mv88e6xxx_num_databases(chip),
+			sizeof(struct mv88e6xxx_devlink_atu_entry),
+			GFP_KERNEL);
 	if (!table)
 		return -ENOMEM;
-
-	memset(table, 0, mv88e6xxx_num_databases(chip) *
-	       sizeof(struct mv88e6xxx_devlink_atu_entry));
-
-	count = 0;
 
 	mv88e6xxx_reg_lock(chip);