Btrfs: remove redundant btrfs_verify_qgroup_counts declaration.

Do like disk-io function declared under CONFIG_BTRFS_FS_RUN_SANITY_TESTS
and keep prototype in qgroup.h only
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/ctree.h

@@ -4126,8 +4126,6 @@ static inline int btrfs_defrag_cancelled(struct btrfs_fs_info *fs_info)
 /* Sanity test specific functions */
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 void btrfs_test_destroy_inode(struct inode *inode);
-int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
-			       u64 rfer, u64 excl);
 #endif
 
 #endif