t4202: fix typo

While I did a

	make -j64 test > ~/t.out

to check my previous patch (in case some test actually tested 'trustctime'
or something), I noticed this one. Somebody has speeling trouble:

	t4202-log.sh: line 345: test_expect_sucess: command not found

Fixed thus.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

t/t4202-log.sh

@@ -342,7 +342,7 @@ cat > expect <<\EOF
 * initial
 EOF
 
-test_expect_sucess 'log --graph with merge' '
+test_expect_success 'log --graph with merge' '
 	git log --graph --date-order --pretty=tformat:%s |
 		sed "s/ *$//" >actual &&
 	test_cmp expect actual