cnic: Use the bitmap API to allocate bitmaps

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.

It is less verbose and it improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/521bd2a49be5d88e493bcfb63505d3df91a1c2d2.1657052743.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/cnic.c

@@ -660,7 +660,7 @@ static int cnic_init_id_tbl(struct cnic_id_tbl *id_tbl, u32 size, u32 start_id,
 	id_tbl->max = size;
 	id_tbl->next = next;
 	spin_lock_init(&id_tbl->lock);
-	id_tbl->table = kcalloc(BITS_TO_LONGS(size), sizeof(long), GFP_KERNEL);
+	id_tbl->table = bitmap_zalloc(size, GFP_KERNEL);
 	if (!id_tbl->table)
 		return -ENOMEM;
 
@@ -669,7 +669,7 @@ static int cnic_init_id_tbl(struct cnic_id_tbl *id_tbl, u32 size, u32 start_id,
 
 static void cnic_free_id_tbl(struct cnic_id_tbl *id_tbl)
 {
-	kfree(id_tbl->table);
+	bitmap_free(id_tbl->table);
 	id_tbl->table = NULL;
 }