t4014: use test_config()

Instead of manually unsetting the config after the test case is done,
use test_config() to do it automatically. While we're at it, fix a typo
in a test case name.

Signed-off-by: Denton Liu <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: Denton-L

t/t4014-format-patch.sh

@@ -1939,10 +1939,9 @@ test_expect_success 'format-patch errors out when history involves criss-cross'
 	test_must_fail 	git format-patch --base=auto -1
 '
 
-test_expect_success 'format-patch format.useAutoBaseoption' '
-	test_when_finished "git config --unset format.useAutoBase" &&
+test_expect_success 'format-patch format.useAutoBase option' '
 	git checkout local &&
-	git config format.useAutoBase true &&
+	test_config format.useAutoBase true &&
 	git format-patch --stdout -1 >patch &&
 	grep "^base-commit:" patch >actual &&
 	git rev-parse upstream >commit-id-base &&
@@ -1951,8 +1950,7 @@ test_expect_success 'format-patch format.useAutoBaseoption' '
 '
 
 test_expect_success 'format-patch --base overrides format.useAutoBase' '
-	test_when_finished "git config --unset format.useAutoBase" &&
-	git config format.useAutoBase true &&
+	test_config format.useAutoBase true &&
 	git format-patch --stdout --base=HEAD~1 -1 >patch &&
 	grep "^base-commit:" patch >actual &&
 	git rev-parse HEAD~1 >commit-id-base &&