code clanup: remove unused samplerate_native

src/libespeak-ng/compiledata.c

 	sr2 = Read4Bytes(f);
 	fseek(f, 40, SEEK_SET);
 
-	if ((sr1 != samplerate_native) || (sr2 != sr1*2)) {
-		if (sr1 != samplerate_native)
-			error(ctx, "Can't resample (%d to %d): %s", sr1, samplerate_native, fname);
+	if ((sr1 != samplerate) || (sr2 != sr1*2)) {
+		if (sr1 != samplerate)
+			error(ctx, "Can't resample (%d to %d): %s", sr1, samplerate, fname);
 		else
 			error(ctx, "WAV file is not mono: %s", fname);
 		return 0;
 		sprintf(phdst, "%s", path_home);
 	}
 
-	samplerate_native = samplerate = rate;
+	samplerate = rate;
 	LoadPhData(NULL, NULL);
 	if (LoadVoice("", 8/*compiling phonemes*/) == NULL) {
 		clean_context(ctx);
 
 	// write a word so that further data doesn't start at displ=0
 	Write4Bytes(ctx->f_phdata, version_phdata);
-	Write4Bytes(ctx->f_phdata, samplerate_native);
+	Write4Bytes(ctx->f_phdata, samplerate);
 	Write4Bytes(ctx->f_phindex, version_phdata);
 
 	memset(ctx->ref_hash_tab, 0, sizeof(ctx->ref_hash_tab));

src/libespeak-ng/synth_mbrola.c

 	mbr_name_prefix = 0;
 
 	if (mbrola_voice == NULL) {
-		samplerate = samplerate_native;
+		samplerate = samplerate;
 		SetParameter(espeakVOICETYPE, 0, 0);
 		return ENS_OK;
 	}

src/libespeak-ng/synthesize.h

 
 extern unsigned char *wavefile_data;
 extern int samplerate;
-extern int samplerate_native;
 
 #define N_ECHO_BUF 5500   // max of 250mS at 22050 Hz
 extern int echo_head;

src/libespeak-ng/voices.c

 	voice->voicing = 64;
 	voice->consonant_amp = 90; // change from 100 to 90 for v.1.47
 	voice->consonant_ampv = 100;
-	voice->samplerate = samplerate_native;
+	voice->samplerate = samplerate;
 	memset(voice->klattv, 0, sizeof(voice->klattv));
 
 	speed.fast_settings = espeakRATE_MAXIMUM;

src/libespeak-ng/wavegen.c

 
 static int PHASE_INC_FACTOR;
 int samplerate = 0; // this is set by Wavegeninit()
-int samplerate_native = 0;
 
 static wavegen_peaks_t peaks[N_PEAKS];
 static int peak_harmonic[N_PEAKS];
 		wavemult_fact = 60; // default
 
 	wvoice = NULL;
-	samplerate = samplerate_native = rate;
+	samplerate = rate;
 	PHASE_INC_FACTOR = 0x8000000 / samplerate; // assumes pitch is Hz*32
 	Flutter_inc = (64 * samplerate)/rate;
 	samplecount = 0;