Regionlist overhaul: Change regl_alloc signature

src/fellow_regionlist.h

@@ -188,9 +188,9 @@ static const int8_t regl_bits = 16;	// XXX 64k reasonable?
 #endif
 
 static struct regl *
-regl_alloc(buddy_t *membuddy)
+regl_alloc(const struct regionlist *rl)
 {
-	return (regl_alloc_bits(membuddy, regl_bits, regl_bits, NULL));
+	return (regl_alloc_bits(rl->membuddy, regl_bits, regl_bits, NULL));
 }
 
 static struct regionlist *
@@ -237,7 +237,7 @@ regionlist_extend(struct regionlist *rl)
 
 	CHECK_OBJ_NOTNULL(rl, REGIONLIST_MAGIC);
 
-	regl = regl_alloc(rl->membuddy);
+	regl = regl_alloc(rl);
 	VSTAILQ_INSERT_TAIL(&rl->head, regl, list);
 	return (regl);
 }