diag: Add wake_up when HSIC driver is finished writing

When the HSIC driver calls the write complete callback function
in the diag kernel driver, diag does not make a wake_up_interuptible
call. There is a chance that the thread in the corresponding
wait_event_interuptible may not be woken up. Make changes to ensure
that the thread that may be waiting is woken up.

Change-Id: I52032913291aec5c775cc2ff7ca69fe78481ea7a
Signed-off-by: Dixon Peterson <dixonp@codeaurora.org>