buildgcc: Do not try to install GCC if build failed

We didn't bail out if configuring or building of GCC failed but run
`make install` and later steps instead. This resulted in very confusing
logs that concealed the actual error.

Change-Id: Ia064e0bfd96f0cbad391da3bb19e4dc304d988ff
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/26496
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed