9p: double iput() in ->lookup() if d_materialise_unique() fails

d_materialise_unique() does iput() itself.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/9p/vfs_inode.c

@@ -841,7 +841,6 @@ inst_out:
 	if (!IS_ERR(res))
 		return res;
 	result = PTR_ERR(res);
-	iput(inode);
 error:
 	p9_client_clunk(fid);