hfsplus: Fix double iput of the same inode in hfsplus_fill_super()

There is a misprint in resource deallocation code on error path in
hfsplus_fill_super(): the sbi->alloc_file inode is iput twice,
while the root inode in not iput at all.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/hfsplus/super.c

@@ -500,7 +500,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 out_put_hidden_dir:
 	iput(sbi->hidden_dir);
 out_put_root:
-	iput(sbi->alloc_file);
+	iput(root);
 out_put_alloc_file:
 	iput(sbi->alloc_file);
 out_close_cat_tree: