generic ipi function calls: wait on alloc failure fallback

When a GFP_ATOMIC allocation fails, it falls back to allocating the
data on the stack and converting it to a waiting call.

Make sure we actually wait in this case.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/smp.c

@@ -312,6 +312,7 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
 	if (!data) {
 		data = &d;
 		data->csd.flags = CSD_FLAG_WAIT;
+		wait = 1;
 	}
 
 	spin_lock_init(&data->lock);