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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>