Cleanup: Remove unused SPAM variable.

The same functionality is already provided by
blaze_util::VerboseLogging() function.

--
Change-Id: I6102ffd985354e666dc8440080de6c35146199cb
MOS_MIGRATED_REVID=90155343
diff --git a/src/main/cpp/blaze_util.h b/src/main/cpp/blaze_util.h
index 43bc708..d4a8410 100644
--- a/src/main/cpp/blaze_util.h
+++ b/src/main/cpp/blaze_util.h
@@ -105,6 +105,7 @@
 blaze_exit_code::ExitCode CheckValidPort(
     const string &str, const string &option, string *error);
 
+// Enable messages mostly of interest to developers.
 bool VerboseLogging();
 
 // Read the JVM version from a file descriptor. The fd should point