proper prototype for blk_dev_init()

This patch adds a proper prototye for blk_dev_init() in block/blk.h

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/genhd.c b/block/genhd.c
index 53f2238..abc6fed 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -17,6 +17,8 @@
 #include <linux/buffer_head.h>
 #include <linux/mutex.h>
 
+#include "blk.h"
+
 static DEFINE_MUTEX(block_class_lock);
 #ifndef CONFIG_SYSFS_DEPRECATED
 struct kobject *block_depr;
@@ -346,8 +348,6 @@
 #endif
 
 
-extern int blk_dev_init(void);
-
 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 {
 	if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)