mtrace: Fix output with PIE and ASLR [BZ #22716]

Record only the relative address of the caller in mtrace file.  Use
LD_TRACE_PRELINKING to get the executable as well as binary vs
executable load offsets so that we may compute a base to add to the
relative address in the mtrace file.  This allows us to get a valid
address to pass to addr2line in all cases.

Fixes BZ #22716.

Co-authored-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Andreas Schwab <schwab@linux-m68k.org>
Reviewed-by: DJ Delorie <dj@redhat.com>