Rather than putting the `rm` at the end of the script before the normal

Rather than putting the `rm` at the end of the script before the normal
exit point, create a trap to automatically delete the script when exiting.
This way the linker script gets cleaned up whenever there is an error as
well.  Otherwise every link invocation that ends in a failure could leave
behind crap.  On my system, i found almost 2 million of these suckers in
my /tmp dir.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>