mmc: Fix re-probing with PM_POST_RESTORE notification

In the error-path where PM notifies PM_POST_RESTORE, the rescan-blockage
should be cleared as well.  Otherwise it'll be never re-probed.

Also, as a bonus, this fixes a bug in S4 with user-mode suspend in the
current code, as it sends PM_POST_RESTORE instead of
PM_POST_HIBERNATION wrongly.

Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Chris Ball <cjb@laptop.org>