t9020: do not use export X=Y

The shell syntax "export X=Y" is not understood by all shells.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9020-remote-svn.sh

@@ -74,7 +74,8 @@ test_expect_success REMOTE_SVN 'mark-file regeneration' '
 '
 
 test_expect_success REMOTE_SVN 'incremental imports must lead to the same head' '
-	export SVNRMAX=3 &&
+	SVNRMAX=3 &&
+	export SVNRMAX &&
 	init_git &&
 	git fetch svnsim &&
 	test_cmp .git/refs/svn/svnsim/master .git/refs/remotes/svnsim/master  &&