cfq: fix build breakage & warnings

* CFQ_WEIGHT_* defined inside CONFIG_BLK_CGROUP causes cfq-iosched.c
  compile failure when the config is disabled.  Move it outside the
  ifdef block.

* Dummy cfqg_stats_*() definitions were lacking inline modifiers
  causing unused functions warning if !CONFIG_CFQ_GROUP_IOSCHED.  Add
  them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index ca0ff7c..64392ac 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -27,13 +27,13 @@
 /* Max limits for throttle policy */
 #define THROTL_IOPS_MAX		UINT_MAX
 
-#ifdef CONFIG_BLK_CGROUP
-
 /* CFQ specific, out here for blkcg->cfq_weight */
 #define CFQ_WEIGHT_MIN		10
 #define CFQ_WEIGHT_MAX		1000
 #define CFQ_WEIGHT_DEFAULT	500
 
+#ifdef CONFIG_BLK_CGROUP
+
 enum blkg_rwstat_type {
 	BLKG_RWSTAT_READ,
 	BLKG_RWSTAT_WRITE,