btrfs: open code and remove btrfs_insert_inode_hash helper

This exists to insert the btree_inode in the super blocks inode hash
table.  Since it's only used for the btree inode move the code to where
we use it in disk-io.c and remove the helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/btrfs_inode.h

@@ -268,13 +268,6 @@ static inline unsigned long btrfs_inode_hash(u64 objectid,
 	return (unsigned long)h;
 }
 
-static inline void btrfs_insert_inode_hash(struct inode *inode)
-{
-	unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);
-
-	__insert_inode_hash(inode, h);
-}
-
 #if BITS_PER_LONG == 32
 
 /*

fs/btrfs/disk-io.c

@@ -2218,6 +2218,8 @@ static void btrfs_init_balance(struct btrfs_fs_info *fs_info)
 static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
 {
 	struct inode *inode = fs_info->btree_inode;
+	unsigned long hash = btrfs_inode_hash(BTRFS_BTREE_INODE_OBJECTID,
+					      fs_info->tree_root);
 
 	inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
 	set_nlink(inode, 1);
@@ -2239,7 +2241,7 @@ static void btrfs_init_btree_inode(struct btrfs_fs_info *fs_info)
 	BTRFS_I(inode)->location.type = 0;
 	BTRFS_I(inode)->location.offset = 0;
 	set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
-	btrfs_insert_inode_hash(inode);
+	__insert_inode_hash(inode, hash);
 }
 
 static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info)