net/fq_impl: 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/c7bf099af07eb497b02d195906ee8c11fea3b3bd.1657377335.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/fq_impl.h

@@ -358,8 +358,7 @@ static int fq_init(struct fq *fq, int flows_cnt)
 	if (!fq->flows)
 		return -ENOMEM;
 
-	fq->flows_bitmap = kcalloc(BITS_TO_LONGS(fq->flows_cnt), sizeof(long),
-				   GFP_KERNEL);
+	fq->flows_bitmap = bitmap_zalloc(fq->flows_cnt, GFP_KERNEL);
 	if (!fq->flows_bitmap) {
 		kvfree(fq->flows);
 		fq->flows = NULL;
@@ -383,7 +382,7 @@ static void fq_reset(struct fq *fq,
 	kvfree(fq->flows);
 	fq->flows = NULL;
 
-	kfree(fq->flows_bitmap);
+	bitmap_free(fq->flows_bitmap);
 	fq->flows_bitmap = NULL;
 }