MAINTAINERS: Remove stale hwmon quilt tree

ftp://pub.kernel.org/pub/linux/kernel/people/groeck/linux-staging/
is not kept up to date, so remove reference to it.
Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>

MAINTAINERS

@@ -2873,7 +2873,6 @@ M:	Guenter Roeck <guenter.roeck@ericsson.com>
 L:	lm-sensors@lm-sensors.org
 W:	http://www.lm-sensors.org/
 T:	quilt kernel.org/pub/linux/kernel/people/jdelvare/linux-2.6/jdelvare-hwmon/
-T:	quilt kernel.org/pub/linux/kernel/people/groeck/linux-staging/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git
 S:	Maintained
 F:	Documentation/hwmon/