t3700: fix broken test under !POSIXPERM

76e368c378 (t3700: fix broken test under !SANITY) explains that the test
'git add --chmod=[+-]x changes index with already added file' can fail
if xfoo3 is still present as a symlink from a previous test and deletes
it with rm(1).  That still leaves it present in the index, which causes
the test to fail if POSIXPERM is not defined.  Get rid of it by calling
"git reset --hard" as well, as 76e368c378 already mentioned in passing.

Helped-by: Adam Dinwoodie <adam@dinwoodie.org>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3700-add.sh

@@ -356,6 +356,7 @@ test_expect_success POSIXPERM,SYMLINKS 'git add --chmod=+x with symlinks' '
 
 test_expect_success 'git add --chmod=[+-]x changes index with already added file' '
 	rm -f foo3 xfoo3 &&
+	git reset --hard &&
 	echo foo >foo3 &&
 	git add foo3 &&
 	git add --chmod=+x foo3 &&