pcidev.c: return null instead of exit(1)

BUG=chromium:478356
BRANCH=none
TEST=still builds

Change-Id: I30b7ac25dcd3aafca095f06ba20b68f71de19786
Signed-off-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/1667507
Reviewed-by: Stefan Reinauer <reinauer@google.com>
1 file changed