Remove dead code related to gettid

The gettid system call is always available now.

Change-Id: Ib78b41781eda182dc8605daf456bbea7ff7c2dc0
diff --git a/media/libmediaplayerservice/MidiFile.cpp b/media/libmediaplayerservice/MidiFile.cpp
index 589c625..7e04523 100644
--- a/media/libmediaplayerservice/MidiFile.cpp
+++ b/media/libmediaplayerservice/MidiFile.cpp
@@ -29,17 +29,12 @@
 #include <libsonivox/eas_reverb.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 #include <system/audio.h>
 
 #include "MidiFile.h"
 
-#ifdef HAVE_GETTID
-static pid_t myTid() { return gettid(); }
-#else
-static pid_t myTid() { return getpid(); }
-#endif
-
 // ----------------------------------------------------------------------------
 
 namespace android {
@@ -455,7 +450,7 @@
     // signal main thread that we started
     {
         Mutex::Autolock l(mMutex);
-        mTid = myTid();
+        mTid = gettid();
         LOGV("render thread(%d) signal", mTid);
         mCondition.signal();
     }