ifdtool: Check if file was opened

Check if the new file could in fact be opened before
writing to it.

Change-Id: I6b2d31bf5c18f657fca4dc14fee2f2d5a2e33080
Found-by: Coverity Scan
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/6477
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed