gdb_dejagnu: print failed tests out.

This prints failed test name out. Also, it ignores
the tests that only appears in the baseline.

BUG=None
TEST=the name of failed tests were printed.

Change-Id: Ie0c3f3d3a092a184a2e941020af62d4e2de40da2
Reviewed-on: https://chrome-internal-review.googlesource.com/145848
Reviewed-by: Simon Que <sque@google.com>
Reviewed-by: Han Shen <shenhan@google.com>
Commit-Queue: Yunlian Jiang <yunlian@google.com>
Tested-by: Yunlian Jiang <yunlian@google.com>
diff --git a/dejagnu/gdb_dejagnu.py b/dejagnu/gdb_dejagnu.py
index cb50d57..a7897dc 100755
--- a/dejagnu/gdb_dejagnu.py
+++ b/dejagnu/gdb_dejagnu.py
@@ -277,13 +277,15 @@
 
   def ResultValidate(self):
     self.PrepareResult()
-    result = 0
+    result = []
     for key, value in self.base_result.items():
       if 'PASS' not in value:
         continue
+      if key not in self.test_result:
+        continue
       test_result = self.test_result[key]
       if 'PASS' not in test_result:
-        result = 1
+        result.append(key)
     return result
 
   def PrepareResult(self):