File overwrite case is explicitly handled, so it is not necessary to
pass RENAME_NOREPLACE to vfs_rename.

Clearing the flag fixes rename operations when the share is a ntfs-3g
mount. The latter uses an older version of fuse with no support for
flags in the ->rename op.

Cc: stable@vger.kernel.org
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>