t4124: move test preparation into the test context

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4124-apply-ws-rule.sh

@@ -423,14 +423,8 @@ test_expect_success 'missing blanks at EOF must only match blank lines' '
 	test_must_fail git apply --ignore-space-change --whitespace=fix patch
 '
 
-sed -e's/Z//' >one <<EOF
-a
-b
-c
-		      Z
-EOF
-
 test_expect_success 'missing blank line should match context line with spaces' '
+	test_write_lines a b c "		      " >one &&
 	git add one &&
 	echo d >>one &&
 	git diff -- one >patch &&
@@ -443,14 +437,8 @@ test_expect_success 'missing blank line should match context line with spaces' '
 	test_cmp expect one
 '
 
-sed -e's/Z//' >one <<EOF
-a
-b
-c
-		      Z
-EOF
-
 test_expect_success 'same, but with the --ignore-space-option' '
+	test_write_lines a b c "		      " >one &&
 	git add one &&
 	echo d >>one &&
 	cp one expect &&