USB: wusbcore: Switch to bitmap_zalloc()

Switch to bitmap_zalloc() to show clearly what we are allocating.
Besides that it returns pointer of bitmap type instead of opaque void *.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/wusbcore/wa-rpipe.c

@@ -470,9 +470,7 @@ int rpipe_get_by_ep(struct wahc *wa, struct usb_host_endpoint *ep,
 int wa_rpipes_create(struct wahc *wa)
 {
 	wa->rpipes = le16_to_cpu(wa->wa_descr->wNumRPipes);
-	wa->rpipe_bm = kcalloc(BITS_TO_LONGS(wa->rpipes),
-			       sizeof(unsigned long),
-			       GFP_KERNEL);
+	wa->rpipe_bm = bitmap_zalloc(wa->rpipes, GFP_KERNEL);
 	if (wa->rpipe_bm == NULL)
 		return -ENOMEM;
 	return 0;
@@ -487,7 +485,7 @@ void wa_rpipes_destroy(struct wahc *wa)
 		dev_err(dev, "BUG: pipes not released on exit: %*pb\n",
 			wa->rpipes, wa->rpipe_bm);
 	}
-	kfree(wa->rpipe_bm);
+	bitmap_free(wa->rpipe_bm);
 }
 
 /*