gpu: host1x: 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.

While at it, remove a useless bitmap_zero() call. The bitmap is already
zero'ed when allocated.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/host1x/channel.c

@@ -21,22 +21,18 @@ int host1x_channel_list_init(struct host1x_channel_list *chlist,
 	if (!chlist->channels)
 		return -ENOMEM;
 
-	chlist->allocated_channels =
-		kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long),
-			GFP_KERNEL);
+	chlist->allocated_channels = bitmap_zalloc(num_channels, GFP_KERNEL);
 	if (!chlist->allocated_channels) {
 		kfree(chlist->channels);
 		return -ENOMEM;
 	}
 
-	bitmap_zero(chlist->allocated_channels, num_channels);
-
 	return 0;
 }
 
 void host1x_channel_list_free(struct host1x_channel_list *chlist)
 {
-	kfree(chlist->allocated_channels);
+	bitmap_free(chlist->allocated_channels);
 	kfree(chlist->channels);
 }