tests: add missing &&

Breaks in a test assertion's && chain can potentially hide
failures from earlier commands in the chain.

Commands intended to fail should be marked with !, test_must_fail, or
test_might_fail.  The examples in this patch do not require that.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9123-git-svn-rebuild-with-rewriteroot.sh

@@ -16,7 +16,7 @@ rm -rf import
 
 test_expect_success 'init, fetch and checkout repository' '
 	git svn init --rewrite-root=http://invalid.invalid/ "$svnrepo" &&
-	git svn fetch
+	git svn fetch &&
 	git checkout -b mybranch ${remotes_git_svn}
 	'