[binutils-gdb] Use delete instead of xfree for gdb_timer

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 0e05cf3a61e1996829359e1c32eedb6820930331 ***

Author: Simon Marchi <simon.marchi@ericsson.com>
Branch: master
Commit: 0e05cf3a61e1996829359e1c32eedb6820930331

Use delete instead of xfree for gdb_timer

gdb_timer objects are new'ed in create_timer, but xfree'd in
poll_timers.  Use delete instead.

gdb/ChangeLog:

	* event-loop.c (poll_timers): Unallocate timer using delete
	instead of xfree.