ltp: Use a legal bad address for mips in setrlimit05.c

ltp: Use a legal bad address for mips in setrlimit05.c

This testcase fails on mips32. The process is killed by SIGBUS which
is not as expect.

This is because:
((void *)-1) is not a legal bad address which causes the process
killed by SIGBUG on mips.

'tst_get_bad_addr()' returns an address that should works on mips
and other arches.

Signed-off-by: Hongzhi.Song <hongzhi.song@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>