posix-timers: Fix inverted SIGEV_NONE logic in common_timer_get()

The refactoring of the posix-timer core to allow better code sharing
introduced inverted logic vs. SIGEV_NONE timers in common_timer_get().

That causes hrtimer_forward() to be called on active timers, which
rightfully triggers the warning hrtimer_forward().

Make sig_none what it says: signal mode == SIGEV_NONE.

Fixes: 91d57ba ("posix-timers: Make use of forward/remaining callbacks")
Reported-by: Ye Xiaolong <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: John Stultz <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]

kernel/time/posix-timers.c

@@ -644,7 +644,7 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
 	struct timespec64 ts64;
 	bool sig_none;
 
-	sig_none = (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE;
+	sig_none = (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE;
 	iv = timr->it_interval;
 
 	/* interval timer ? */