Go back to $test_dirs after each test run or tests dir run
Otherwise, we get an error for the 2nd dir if specifying 2 directories e.g.

  perl tests/vg_regtest cachegrind/tests callgrind/tests
  -- Running  tests in cachegrind/tests ----------------------------------
  chdir:           valgrind   ./chdir 
  clreq:           valgrind   -q ./clreq 
  dlclose:         valgrind   ./dlclose 
  notpower2:       valgrind   --I1=32768,8,64 --D1=24576,6,64 --LL=3145728,12,64 ./../../tests/true 
  wrap5:           valgrind   ./../../memcheck/tests/wrap5 
  -- Running  tests in cachegrind/tests/x86 ------------------------------
  fpu-28-108:      valgrind   ./fpu-28-108 
  -- Finished tests in cachegrind/tests/x86 ------------------------------
  -- Finished tests in cachegrind/tests ----------------------------------
  `callgrind/tests' neither a directory nor a readable test file/name



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14487 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/tests/vg_regtest.in b/tests/vg_regtest.in
index d77916f..795369f 100755
--- a/tests/vg_regtest.in
+++ b/tests/vg_regtest.in
@@ -670,8 +670,8 @@
         my $file = `basename $f`;   chomp $file;
         chdir($dir) or die "Could not change into $dir\n";
         do_one_test($dir, $file);
-        chdir($tests_dir);
     }
+    chdir($tests_dir);
 }
 summarise_results();