get_maintainer: fix usage comment

With the `s' it just won't work.

Signed-off-by: Roel Kluin <[email protected]>
Acked-by: Joe Perches <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed