util/xcompile/xcompile: use env(1) to find bash

Not all systems put bash at /bin/bash.

Change-Id: Ib58cd2f6cf330b5b2678d55bb929696872fba9c9
Signed-off-by: Jonathan A. Kollasch <jakllsch@kollasch.net>
Reviewed-on: http://review.coreboot.org/10808
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed