Print more output at the end, when a linter fails.

Bug: 3827
Change-Id: I323241fb0194cac4831af189b94f0e97f374d4c6
diff --git a/cobaltb.py b/cobaltb.py
index ec9be99..2adba5f 100755
--- a/cobaltb.py
+++ b/cobaltb.py
@@ -252,9 +252,28 @@
 
 def _lint(args):
   status = 0
-  status += clang_tidy.main(args.directory)
-  status += golint.main()
-  status += gnlint.main()
+  failure_list = []
+
+  result = clang_tidy.main(args.directory)
+  failure_list.append(('clang_tidy', result))
+  status += result
+
+  result = golint.main()
+  failure_list.append(('golint', result))
+  status += result
+
+  result = gnlint.main()
+  failure_list.append(('gnlint', result))
+  status += result
+
+
+  if status > 0:
+    print('')
+    print('******************* SOME LINTERS FAILED *******************')
+    for linter, result in failure_list:
+      print('%s returned: %s' % (linter, result))
+  else:
+    print('All linters passed')
 
   exit(status)