doc/features: remove duplicate word in distribution feature ext2

(From yocto-docs rev: fa846606014a85154b63794a17ff1d9aacc1a7bc)

Signed-off-by: Jörg Sommer <joerg.sommer@navimatix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

documentation/ref-manual/features.rst

@@ -129,7 +129,7 @@ metadata:
 
 -  *directfb:* Include DirectFB support.
 
--  *ext2:* Include tools for supporting for devices with internal
+-  *ext2:* Include tools for supporting devices with internal
    HDD/Microdrive for storing files (instead of Flash only devices).
 
 -  *ipsec:* Include IPSec support.