Refactor "Suppressions used" printing code in memcheck and tsan analyzer scripts

tools/valgrind/tsan/suppressions.txt

 # There are a few kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 312 matching lines @@
   ThreadSanitizer:Race
   fun:*URLFetcherCancelTest*TestContextReleased*
 }
 {
   Data race on bool in chrome/browser/net/url_fetcher_unittest (2)
   ThreadSanitizer:Race
   fun:*CancelTestURLRequestContext*CancelTestURLRequestContext*
 }
 
 {
-  ThreadSanitizer sanity test (ToolsSanityTest.DataRace).
+  ThreadSanitizer sanity test (ToolsSanityTest.DataRace)
   ThreadSanitizer:Race
   fun:*TOOLS_SANITY_TEST_CONCURRENT_THREAD::ThreadMain
 }
 
 {
   Benign race (or even a false positive) on atomics in ThreadCollisionWarner
   ThreadSanitizer:Race
   fun:base::subtle::NoBarrier_Store
   fun:base::ThreadCollisionWarner::Leave
 }
@@ skipping 337 matching lines @@
 {
    bug_104769
    ThreadSanitizer:Race
    fun:timeout_correct
    fun:event_base_loop
    fun:base::MessagePumpLibevent::Run
    fun:MessageLoop::RunInternal
    fun:MessageLoop::RunHandler
    fun:MessageLoop::Run
 }