Cleanup: Remove unnecessary double-semicolons.

The entries were found by the following command line:

$ find . -regex ".*\.[cChH]\(pp\)?" | xargs git grep -e ';;' --and --not
-e 'for *(.*;;'

Which is a combination of http://stackoverflow.com/a/3858879 and
http://gitster.livejournal.com/27674.html

BUG=None
R=mtklein@google.com

Review URL: https://codereview.chromium.org/1088763005
diff --git a/tests/HashTest.cpp b/tests/HashTest.cpp
index c1bdf88..8489861 100644
--- a/tests/HashTest.cpp
+++ b/tests/HashTest.cpp
@@ -42,7 +42,7 @@
         map.set(i, 2.0*i);
     }
     for (int i = 0; i < N; i++) {
-        double* found = map.find(i);;
+        double* found = map.find(i);
         REPORTER_ASSERT(r, found);
         REPORTER_ASSERT(r, *found == i*2.0);
     }