tests: fix negated test_i18ngrep calls
The helper function test_i18ngrep pretends that it found the expected
results when it is running under GETTEXT_POISON. For this reason, it must
not be used negated like so
! test_i18ngrep foo bar
because the test case would fail under GETTEXT_POISON. The function offers
a special syntax to test that a pattern is *not* found:
test_i18ngrep ! foo bar
Convert incorrect uses to this syntax.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>