logtags: Support # line comments.

Allow # line comments to start anywhere in a line, not just in column 0.

Test: Added trailing # comments to SecurityLogTags.logtags and checked
      that 'make droid' still worked.
Test: Piped a few example lines through a small test script to verify
      that the following line behaved as expected:
      line = re.sub('#.*$', '', line)

Change-Id: Ib7904620adf8da7d11511ef6d8300e5fb4c73c29

tools/event_log_tags.py

@@ -62,9 +62,9 @@ class TagFile(object):
     try:
       for self.linenum, line in enumerate(file_object):
         self.linenum += 1
-
+        line = re.sub('#.*$', '', line) # strip trailing comments
         line = line.strip()
-        if not line or line[0] == '#': continue
+        if not line: continue
         parts = re.split(r"\s+", line, 2)
 
         if len(parts) < 2: