Several tests: cd inside subshell instead of around

Fixed all places where it was a straightforward change from cd'ing into a
directory and back via "cd .." to a cd inside a subshell.

Found these places with "git grep -w "cd \.\.".

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9127-git-svn-partial-rebuild.sh

@@ -9,27 +9,27 @@ test_description='git svn partial-rebuild tests'
 test_expect_success 'initialize svnrepo' '
 	mkdir import &&
 	(
-		cd import &&
+		(cd import &&
 		mkdir trunk branches tags &&
-		cd trunk &&
-		echo foo > foo &&
-		cd .. &&
+		(cd trunk &&
+		echo foo > foo
+		) &&
 		svn_cmd import -m "import for git-svn" . "$svnrepo" >/dev/null &&
 		svn_cmd copy "$svnrepo"/trunk "$svnrepo"/branches/a \
-			-m "created branch a" &&
-		cd .. &&
+			-m "created branch a"
+		) &&
 		rm -rf import &&
 		svn_cmd co "$svnrepo"/trunk trunk &&
-		cd trunk &&
+		(cd trunk &&
 		echo bar >> foo &&
-		svn_cmd ci -m "updated trunk" &&
-		cd .. &&
+		svn_cmd ci -m "updated trunk"
+		) &&
 		svn_cmd co "$svnrepo"/branches/a a &&
-		cd a &&
+		(cd a &&
 		echo baz >> a &&
 		svn_cmd add a &&
-		svn_cmd ci -m "updated a" &&
-		cd .. &&
+		svn_cmd ci -m "updated a"
+		) &&
 		git svn init --stdlayout "$svnrepo"
 	)
 '
@@ -41,11 +41,11 @@ test_expect_success 'import an early SVN revision into git' '
 test_expect_success 'make full git mirror of SVN' '
 	mkdir mirror &&
 	(
-		cd mirror &&
+		(cd mirror &&
 		git init &&
 		git svn init --stdlayout "$svnrepo" &&
-		git svn fetch &&
-		cd ..
+		git svn fetch
+		)
 	)
 '