make test-pull-permission cleanup correctly in case of errors

tests/test-pull-permission

@@ -12,9 +12,8 chmod -w .hg
 cd ..
 
 hg clone a b
+
+chmod +w a/.hg # let test clean up
+
 cd b
 hg verify
-
-cd ..
-
-chmod +w a/.hg # let test clean up