Previously it padded out the entire response buffer with null, which
caused an EC capable of returning large responses to overflow the AP's
input buffer.
BUG=chrome-os-partner:20525
BRANCH=none
TEST=from EC console, 'hcdebug on'
from U-boot console, 'crosec version'
HC resp for HC 0x04 should have only a single 00 byte at the end
Change-Id: I65826c1ccda15f18a59a6c34db61ee67e90511b8
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/60133
Reviewed-by: Simon Glass <sjg@chromium.org>