[autotest] Clean up _format_anchor_text()

BUG=chromium:672348
TEST=None

Change-Id: I7dccf0d9ddc15c4118a1d26e15a2a0af77233bcf
Reviewed-on: https://chromium-review.googlesource.com/566074
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
diff --git a/site_utils/run_suite.py b/site_utils/run_suite.py
index 8629617..63487cc 100755
--- a/site_utils/run_suite.py
+++ b/site_utils/run_suite.py
@@ -527,16 +527,13 @@
         """Format anchor text given a prefix and info strings.
 
         @param prefix        The prefix of the anchor text.
-        @param info_strings  The infos presented in the anchor text.
+        @param info_strings  Iterable of strings.
         @return A anchor_text with the right prefix and info strings.
         """
-        anchor_text = '[{prefix}]: {anchor}'.format(
+        return '[{prefix}]: {anchor}: {info}'.format(
             prefix=prefix,
-            anchor=self.anchor.strip())
-        if info_strings:
-            info_text = ', '.join(info_strings)
-            anchor_text += ': ' + info_text
-        return anchor_text
+            anchor=self.anchor.strip(),
+            info=', '.join(info_strings))
 
     @property
     def text_link(self):