flashrom.c: allow - as filename for stdin

Allows - as filename for -w/-v options. It is sometimes useful to
script flashrom and allowing it to work with pipes allows for more
flexibility in this specific use-case.

Signed-off-by: Daniel Campello <campello@chromium.org>
Change-Id: I97889cfdf7ba9a257e182c4ee2b20075cfa58d4d
Reviewed-on: https://review.coreboot.org/c/flashrom/+/52383
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
2 files changed