dm vdo: use get_random_u32() where appropriate

Use the typed random integer helpers instead of
get_random_bytes() when filling a single integer variable.
The helpers return the value directly, require no pointer
or size argument, and better express intent.

Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

drivers/md/dm-vdo/indexer/index-layout.c

@@ -282,7 +282,7 @@ static void create_unique_nonce_data(u8 *buffer)
 	u32 rand;
 	size_t offset = 0;
 
-	get_random_bytes(&rand, sizeof(u32));
+	rand = get_random_u32();
 	memcpy(buffer + offset, &now, sizeof(now));
 	offset += sizeof(now);
 	memcpy(buffer + offset, &rand, sizeof(rand));