test/helpers: add t_destroy_buffers() helper

Just undoes what t_create_buffers() did.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/test/helpers.c b/test/helpers.c
index e84aaa7..2b40ef2 100644
--- a/test/helpers.c
+++ b/test/helpers.c
@@ -120,6 +120,18 @@
 	return vecs;
 }
 
+void t_destroy_buffers(struct iovec *vecs, int nr_vecs)
+{
+	int i;
+
+	if (!vecs)
+		return;
+
+	for (i = 0; i < nr_vecs; i++)
+		free(vecs[i].iov_base);
+	free(vecs);
+}
+
 /*
  * Helper for setting up an io_uring instance, skipping if the given user isn't
  * allowed to.
diff --git a/test/helpers.h b/test/helpers.h
index 9e1cdf5..b2be2ca 100644
--- a/test/helpers.h
+++ b/test/helpers.h
@@ -69,6 +69,11 @@
 struct iovec *t_create_buffers(size_t buf_num, size_t buf_size);
 
 /*
+ * Helper for freeing buffers created with t_create buffers
+ */
+void t_destroy_buffers(struct iovec *vecs, int nr_vecs);
+
+/*
  * Helper for creating connected socket pairs
  */
 int t_create_socket_pair(int fd[2], bool stream);