Switch from using 'nacl_main' to 'main' entry point

ports/alut-demo/alut_hello_world.c

 #include <stdlib.h>
 #include <stdio.h>
 #include <AL/alut.h>
 
-#include <ppapi_simple/ps_main.h>
 #include <ppapi/c/ppb.h>
+#include <ppapi_simple/ps.h>
 
 /*
   This is the 'Hello World' program from the ALUT
   reference manual.
 
   Link using '-lalut -lopenal -lpthread'.
 */
 
 void alSetPpapiInfo(PP_Instance instance, PPB_GetInterface get_interface);
 
-int nacl_main(int argc, char** argv) {
+int main(int argc, char** argv) {
   ALuint helloBuffer, helloSource;
 
   /*
    * This extra line is required by the underlying openAl
    * NaCl port.
    */
   alSetPpapiInfo(PSGetInstanceId(), PSGetInterface);
 
   alutInit(&argc, argv);
   helloBuffer = alutCreateBufferHelloWorld();
   alGenSources(1, &helloSource);
   alSourcei(helloSource, AL_BUFFER, helloBuffer);
   alSourcePlay(helloSource);
   alutSleep(1);
   alutExit();
   return EXIT_SUCCESS;
 }
-
-PPAPI_SIMPLE_REGISTER_MAIN(nacl_main)