cgpt: Reuse ReadFile from host_misc in cmd_find

Remove the duplicate static ReadFile() helper in cgpt/cmd_find.c and
reuse ReadFile() from host_misc.c.

BUG=b:124141368
TEST=make runtests
BRANCH=none
TAG=agy
CONV=2efa1fd4-161e-459c-95ac-49f549088989

Change-Id: Icb940455845379dd3ef3ec231da6cb458ca8b369
Signed-off-by: Jakub Czapiga <czapiga@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/8497144
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
1 file changed