t: convert fgrep usage to "grep -F"

Despite POSIX states that:

> The old egrep and fgrep commands are likely to be supported for many
> years to come as implementation extensions, allowing historical
> applications to operate unmodified.

GNU grep 3.8 started to warn[1]:

> The egrep and fgrep commands, which have been deprecated since
> release 2.5.3 (2007), now warn that they are obsolescent and should
> be replaced by grep -E and grep -F.

Prepare for their removal in the future.

[1]: https://lists.gnu.org/archive/html/info-gnu/2022-09/msg00001.html

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index e18a218952..f6aebe92ff 100755
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -49,7 +49,7 @@ test_expect_success 'result is really identical' '
 test_expect_success 'rewrite bare repository identically' '
 	(git config core.bare true && cd .git &&
 	 git filter-branch branch > filter-output 2>&1 &&
-	! fgrep fatal filter-output)
+	! grep fatal filter-output)
 '
 git config core.bare false
 test_expect_success 'result is really identical' '
@@ -506,7 +506,7 @@ test_expect_success 'rewrite repository including refs that point at non-commit
 	git tag -a -m "tag to a tree" treetag $new_tree &&
 	git reset --hard HEAD &&
 	git filter-branch -f -- --all >filter-output 2>&1 &&
-	! fgrep fatal filter-output
+	! grep fatal filter-output
 '
 
 test_expect_success 'filter-branch handles ref deletion' '