bcache: Build fixes from test robot

config: make ARCH=i386 allmodconfig

All error/warnings:

   drivers/md/bcache/bset.c: In function 'bch_ptr_bad':
>> drivers/md/bcache/bset.c:164:2: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/debug.c: In function 'bch_pbtree':
>> drivers/md/bcache/debug.c:86:4: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/btree.c: In function 'bch_btree_read_done':
>> drivers/md/bcache/btree.c:245:8: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/closure.o: In function `closure_debug_init':
>> (.init.text+0x0): multiple definition of `init_module'
>> drivers/md/bcache/super.o:super.c:(.init.text+0x0): first defined here

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/bcache/closure.c b/drivers/md/bcache/closure.c
index d6fbec0..f54f7c9 100644
--- a/drivers/md/bcache/closure.c
+++ b/drivers/md/bcache/closure.c
@@ -334,14 +334,12 @@
 	.release	= single_release
 };
 
-int __init closure_debug_init(void)
+void __init closure_debug_init(void)
 {
 	debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
 	return 0;
 }
 
-module_init(closure_debug_init);
-
 #endif
 
 MODULE_AUTHOR("Kent Overstreet <koverstreet@google.com>");