Input: zforce_ts - ensure that pm_stay_awake() and pm_relax() are balanced

Input: zforce_ts - ensure that pm_stay_awake() and pm_relax() are balanced

There is a small chance that ts->suspending flag may change while the
interrupt handler is running. To make sure call to pm_relax() is not
skipped on accident use a temporary to hold the original value at the
beginning of interrupt. Use READ_ONCE() so that the value is actually
fetched at the right time.

Tested-by: Andreas Kemnade <andreas@kemnade.info> # Tolino Shine2HD
Link: https://lore.kernel.org/r/20240824055047.1706392-8-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>