arch/x86/Makefile.inc: Update symbol check macro

This was breaking the build on OS X, but also wasn't working correctly
under linux anymore either. It wouldn't print the illegal symbols
when it failed.

- Split the generation of the offenders file from the actual check for
offending symbols and just send all output to /dev/null.
- Rewrite the check for offending symbols in a way that works with OS X.

Tested by adding a global variable to romstage and verifying the
failure is shown correctly.  Verified that it works correctly with no
illegal variables.

Change-Id: I5b3ac32448851884d78c3b3449508ffe014119ab
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/13018
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

0 files changed, 0 insertions, 0 deletions