UWB: Return UWB_RSV_ALLOC_NOT_FOUND rather than crashing on NULL dereference if kzalloc fails

Crashing on a null pointer deref is never a nice thing to do. It seems
to me that it's better to simply return UWB_RSV_ALLOC_NOT_FOUND if
kzalloc() fails in uwb_rsv_find_best_allocation().

Signed-off-by: Jesper Juhl <[e-mail]>
Acked-by: David Vrabel <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/uwb/allocator.c

···
 	int bit_index;
 
 	ai = kzalloc(sizeof(struct uwb_rsv_alloc_info), GFP_KERNEL);
-	
+	if (!ai)
+		return UWB_RSV_ALLOC_NOT_FOUND;
 	ai->min_mas = rsv->min_mas;
 	ai->max_mas = rsv->max_mas;
 	ai->max_interval = rsv->max_interval;