Annotate logcat with current running test (oemcrypto)

Merge from widevine repo of http://go/wvgerrit/14125

This copies code from http://go/wvgerrit/13847 to the oemcrypto unit
tests.  It puts the test name in the log file.

I also commented out some unused function parameters to avoid compiler
warnings.

Change-Id: I3ba259de2f408ec60e90db7f0ea1524d5aa8f8a4

libwvdrmengine/cdm/src/log.cpp

@@ -26,9 +26,10 @@ namespace wvcdm {
 
 LogPriority g_cutoff = LOG_VERBOSE;
 
-void InitLogging(int argc, const char* const* argv) {}
+void InitLogging(int /* argc */, const char* const* /* argv */) {}
 
-void Log(const char* file, int line, LogPriority level, const char* fmt, ...) {
+void Log(const char* /* file */, int /* line */, LogPriority level,
+         const char* fmt, ...) {
   va_list ap;
   char buf[LOG_BUF_SIZE];
   va_start(ap, fmt);