scsi: pm: Balance pm_only of request queue during system resume

During system resume, scsi_resume_device() decreases a request queue's
pm_only counter if the scsi device was quiesced before. But after that,
if the scsi device's RPM status is RPM_SUSPENDED, the pm_only counter is
still held (non-zero). Current scsi resume hook only sets the RPM status
of the scsi device and its request queue to RPM_ACTIVE, but leaves the
pm_only counter unchanged. This may make the request queue's pm_only
counter remain non-zero after resume hook returns, hence those who are
waiting on the mq_freeze_wq would never be woken up. Fix this by calling
blk_post_runtime_resume() if this sdev's RPM status was RPM_SUSPENDED.

Change-Id: I11736dae2d3e79fc940f97433da89b89e2de9044
Signed-off-by: Can Guo <cang@codeaurora.org>