maple: fix wrong return value of maple_bus_init().

If KMEM_CACHE or maple_alloc_dev failed, the maple_bus_init() will return 0
rather than error, because the retval is not changed after KMEM_CACHE or
maple_alloc_dev failed.

Fixes: 17be2d2 ("sh: Add maple bus support for the SEGA Dreamcast.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Lu Wei <luwei32@huawei.com>
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Rich Felker <dalias@libc.org>

Author: Lu Wei

drivers/sh/maple/maple.c

@@ -834,8 +834,10 @@ static int __init maple_bus_init(void)
 
 	maple_queue_cache = KMEM_CACHE(maple_buffer, SLAB_HWCACHE_ALIGN);
 
-	if (!maple_queue_cache)
+	if (!maple_queue_cache) {
+		retval = -ENOMEM;
 		goto cleanup_bothirqs;
+	}
 
 	INIT_LIST_HEAD(&maple_waitq);
 	INIT_LIST_HEAD(&maple_sentq);
@@ -848,6 +850,7 @@ static int __init maple_bus_init(void)
 		if (!mdev[i]) {
 			while (i-- > 0)
 				maple_free_dev(mdev[i]);
+			retval = -ENOMEM;
 			goto cleanup_cache;
 		}
 		baseunits[i] = mdev[i];