cbfstool: Fix tolower() calls on Cygwin

Cygwin complains:

cbfstool.c: 1075:5 error: array subscript has type 'char' [-Werror=char-subscripts]

so add an explicit cast.

Change-Id: Ie89153518d6af2bacce3f48fc7952fee17a688dd
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: http://review.coreboot.org/11666
Tested-by: build bot (Jenkins)
Reviewed-by: Zheng Bao <zheng.bao@amd.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

0 files changed, 0 insertions, 0 deletions