staging: gpib: Replace semaphore with completion for one-time signaling

staging: gpib: Replace semaphore with completion for one-time signaling

Replaced 'down_interruptible()' and 'up()' calls
with 'wait_for_completion_interruptible()' and
'complete()' respectively. The completion API
simplifies the code and adheres to kernel best
practices for synchronization primitive

Signed-off-by: Santosh Mahto <eisantosh95@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20241212162112.13083-1-eisantosh95@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>