checkasm: replace gettimeofday with clock_gettime

tests/checkasm/checkasm.c:55:5: warning: implicit declaration of function 'gettimeofday' is invalid in C99 [-Wimplicit-function-declaration]
    gettimeofday(&tv, NULL);
    ^
27 jobs for freebsd in 14 minutes and 26 seconds (queued for 1 second)
Status Job ID Name Coverage
  Style
passed #294004
amd64 debian
style-check

00:00:23

 
  Build
passed #294005
amd64 debian
build-debian

00:00:43

passed #294013
debian aarch64
build-debian-aarch64

00:01:17

passed #294014
debian aarch64
build-debian-aarch64-clang-5

00:01:13

passed #294017
debian armv7
build-debian-armv7

00:02:34

passed #294018
debian armv7
build-debian-armv7-clang-5

00:01:10

passed #294020
docker ppc64le
build-debian-ppc64le

00:00:50

passed #294006
amd64 debian
build-debian-static

00:00:42

passed #294016
debian aarch64
build-debian-werror

00:00:38

passed #294007
amd64 debian
build-debian32

00:00:42

passed #294885
macos
build-macos

00:00:50

passed #294019
amd64 debian allowed to fail
build-ubuntu-snap

00:00:47

passed #294011
amd64 debian
build-win-arm32

00:00:30

passed #294012
amd64 debian
build-win-arm64

00:00:31

passed #294008
amd64 debian
build-win32

00:00:44

passed #294009
amd64 debian
build-win32-unaligned-stack

00:00:43

passed #294010
amd64 debian
build-win64

00:00:50

failed #294015
macos
build-macos

 
  Test
passed #294021
amd64 debian
test-debian

00:00:46

passed #294027
debian aarch64
test-debian-aarch64

00:02:04

passed #294029
debian armv7
test-debian-armv7-clang-5

00:02:17

passed #294023
amd64 debian
test-debian-asan

00:02:15

passed #294024
amd64 debian
test-debian-msan

00:01:03

passed #294028
docker ppc64le
test-debian-ppc64le

00:01:12

passed #294025
amd64 debian
test-debian-ubsan

00:01:30

passed #294022
amd64 debian
test-debian-unaligned-stack

00:00:48

passed #294026
amd64 debian
test-win64

00:01:02