t4200: remove two unnecessary lines

These two lines appear to be unnecessary.  They set variables which are not
used afterwards.  The primary motivation to remove them is that the sed
invocation exits non-zero for seds which require newline termination of
input files.
Signed-off-by: NBrandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

t/t4200-rerere.sh

@@ -190,8 +190,6 @@ test_expect_success 'file2 added differently in two branches' '
 	git add file2 &&
 	git commit -m version2 &&
 	test_must_fail git merge fourth &&
-	sha1=$(sed -e "s/	.*//" .git/MERGE_RR) &&
-	rr=.git/rr-cache/$sha1 &&
 	echo Cello > file2 &&
 	git add file2 &&
 	git commit -m resolution