mei: init: Flush scheduled work before resetting the device

Flushing pending work items before resetting the device makes more
sense than doing so afterwards. Some of them, like e.g. the NFC
initialization one, find themselves with client IDs changed after
the reset, eventually leading to trigger a client.c:mei_me_cl_by_id()
warning after a few modprobe/rmmod cycles.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>