util/abuild: Don't set XGCCPATH if it's in the environment

Change-Id: I0fa231ca3d33300a671810e994c5be54ac10a18b
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/17723
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
1 file changed