Sometimes resume= parameter comes in integer style (e.g. major:minor)
and then name_to_dev_t can not detect partition properly. (especially
async device like usb, mmc).

This patch calls get_gendisk() if resumewait is true and resume_file
is in integer format to work around this problem.
Signed-off-by: NMinho Ban <mhban@samsung.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>