Don't do a call as the first instruction in libpayload.

Don't do a call as the first instruction in libpayload.

Doing a call before the payload has set up its stack is risky. The stack may
not be in a favorable location. Normally this is not an issue with coreboot
or other well behaved callers.

Change-Id: Ie6f6748a471324b29ebad045c807dfc9f4b92034
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: http://review.coreboot.org/240
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>