busybox

chgrp: correct the usage for non-desktop chgrp calls

When IF_DESKTOP is not defined, chown and chgrp only takes option -R -h,
However the usage output of chgrp is wrong:

	$ ./busybox.nosuid chown
	Usage: chown [-Rh]... USER[:[GRP]] FILE...

	$ ./busybox.nosuid chgrp
	Usage: chgrp [-RhLHP]... GROUP FILE...

	$ ./busybox.nosuid chgrp -H group dummy
	chgrp: invalid option -- 'H'
	Usage: chgrp [-RhLHP]... GROUP FILE...

The chgrp is now a wrapper of chown, so the recognized options shall be the same.
This is introduced by 34425389e09353a8dacdd6b23a62553f699c544c

I would expect the correct behavior shall be the same as chown.
So suggest the below patch, the behavior shall be:

	$ ./busybox.nosuid chgrp
	Usage: chgrp [-Rh]... GROUP FILE...

Signed-off-by: Shuang Liu <sliu@de.adit-jv.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>