inetutils: fix libreadline path to fix QA errors

If wrong path set, inetutils configure script will add a absolute
rpath, which result in the below QA errors:
| ERROR: QA Issue: package inetutils-ftp contains bad RPATH
| ERROR: QA Issue: package inetutils-telnet contains bad RPATH
| ERROR: QA Issue: package inetutils-telnetd contains bad RPATH
| ERROR: QA run found fatal errors. Please consider fixing them.
| ERROR: Function failed: do_package_qa

Signed-off-by: Ting Liu <b28495@freescale.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>