objpool: fix flag initialisation

We compare flags on repeated allocations from an existing pool, but
initialisation got forgotten in the process. Restore it.

Fixes: d6e6ac5 ("Add a object pool allocator")
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/lib/objpool.c

@@ -94,6 +94,7 @@ void *objpool_alloc(struct objpool_head *head, size_t size, uint32_t flags)
 	unsigned int new_n;
 
 	if (list_is_empty(&head->list)) {
+		head->flags = flags;
 		new_n = 2;
 	} else {
 		/* Check the last one */