librtlsdr: remove unneeded casting

Signed-off-by: Hoernchen <la@tfc-server.de>

src/librtlsdr.c

@@ -861,7 +861,7 @@ int rtlsdr_get_tuner_gains(rtlsdr_dev_t *dev, int *gains)
 				     445, 480, 496 };
 	const int unknown_gains[] = { 0 /* no gain values */ };
 
-	int *ptr = NULL;
+	const int *ptr = NULL;
 	int len = 0;
 
 	if (!dev)
@@ -869,22 +869,22 @@ int rtlsdr_get_tuner_gains(rtlsdr_dev_t *dev, int *gains)
 
 	switch (dev->tuner_type) {
 	case RTLSDR_TUNER_E4000:
-		ptr = (int *)e4k_gains; len = sizeof(e4k_gains);
+		ptr = e4k_gains; len = sizeof(e4k_gains);
 		break;
 	case RTLSDR_TUNER_FC0012:
-		ptr = (int *)fc0012_gains; len = sizeof(fc0012_gains);
+		ptr = fc0012_gains; len = sizeof(fc0012_gains);
 		break;
 	case RTLSDR_TUNER_FC0013:
-		ptr = (int *)fc0013_gains; len = sizeof(fc0013_gains);
+		ptr = fc0013_gains; len = sizeof(fc0013_gains);
 		break;
 	case RTLSDR_TUNER_FC2580:
-		ptr = (int *)fc2580_gains; len = sizeof(fc2580_gains);
+		ptr = fc2580_gains; len = sizeof(fc2580_gains);
 		break;
 	case RTLSDR_TUNER_R820T:
-		ptr = (int *)r820t_gains; len = sizeof(r820t_gains);
+		ptr = r820t_gains; len = sizeof(r820t_gains);
 		break;
 	default:
-		ptr = (int *)unknown_gains; len = sizeof(unknown_gains);
+		ptr = unknown_gains; len = sizeof(unknown_gains);
 		break;
 	}