docs: Remove duplicate word

Delete duplicate words of "the".
Signed-off-by: Deming Wang <wangdeming@inspur.com>
Link: https://lore.kernel.org/r/20220624014605.2007-1-wangdeming@inspur.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/filesystems/overlayfs.rst

@@ -607,7 +607,7 @@ can be removed.
 User xattr
 ----------
 
-The the "-o userxattr" mount option forces overlayfs to use the
+The "-o userxattr" mount option forces overlayfs to use the
 "user.overlay." xattr namespace instead of "trusted.overlay.".  This is
 useful for unprivileged mounting of overlayfs.