cfq-iosched: move IO controller declerations to a header file

They should not be declared inside some other file that's not related
to CFQ.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/blk-cgroup.c

@@ -14,9 +14,7 @@
 #include <linux/seq_file.h>
 #include <linux/kdev_t.h>
 #include "blk-cgroup.h"
-
-extern void cfq_unlink_blkio_group(void *, struct blkio_group *);
-extern void cfq_update_blkio_group_weight(struct blkio_group *, unsigned int);
+#include "cfq-iosched.h"
 
 struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
 

block/cfq-iosched.c

@@ -14,6 +14,7 @@
 #include <linux/ioprio.h>
 #include <linux/blktrace_api.h>
 #include "blk-cgroup.h"
+#include "cfq-iosched.h"
 
 /*
  * tunables

block/cfq-iosched.h

+#ifndef CFQ_IOSCHED_H
+#define CFQ_IOSCHED_H
+
+void cfq_unlink_blkio_group(void *, struct blkio_group *);
+void cfq_update_blkio_group_weight(struct blkio_group *, unsigned int);
+
+#endif