util-linux-ng: fix readprofile update-alternatives vs busybox

util-linux-ng: fix readprofile update-alternatives vs busybox

* util-linux-ng installs readprofile in /sbin, busybox installs
it in /usr/sbin which tiggers the following log when configuring
the package :
Configuring util-linux-ng-readprofile.
update-alternatives: Error: cannot register alternative readprofile to
/sbin/readprofile since it is already registered to /usr/sbin/readprofile
Collected errors:
 * pkg_run_script: postinst script returned status 1.
 * opkg_configure: util-linux-ng-readprofile.postinst returned 1.

* the fix is to have util-linux-ng install readprofile in /usr/sbin

* this patch fix http://bugs.openembedded.org/show_bug.cgi?id=5474 as
suggested by Tom Rini

Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Tom Rini <tom_rini@mentor.com>
Tested-by: Philip Balister <philip@balister.org>