Set recovery flags so that recovery restarts when DM device is resumed.
When a device-mapper device is suspended, all I/O must stop. This is done by
calling 'md_stop_writes' and 'mddev_suspend'. These calls in-turn manipulate
the recovery flags - including setting 'MD_RECOVERY_FROZEN'. The DM device
may have been suspended while recovery was not yet complete, so the process
needs to pick-up where it left off. Since 'mddev_resume' does not unset
'MD_RECOVERY_FROZEN' and set 'MD_RECOVERY_NEEDED', we must do it ourselves before
Signed-off-by: Jonathan Brassow <email@example.com>