PM: hibernate: Remove blk_status_to_errno in hib_wait_io

blk_status_to_errno doesn't appear to perform extra work besides
converting blk_status_t to integer. This patch removes that unnecessary
conversion as the return type of the function is blk_status_t.

Signed-off-by: Falla Coulibaly <fallacoulibalyz@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>