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 <jj@chaosbits.net>
Acked-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/uwb/allocator.c

@@ -326,7 +326,8 @@ int uwb_rsv_find_best_allocation(struct uwb_rsv *rsv, struct uwb_mas_bm *availab
 	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;