macOS: Fix build warnings (#374)

Author: triplef

mac/hid.c

@@ -381,7 +381,7 @@ static struct hid_device_info *create_device_info_with_usage(IOHIDDeviceRef dev,
 	struct hid_device_info *cur_dev;
 	io_object_t iokit_dev;
 	kern_return_t res;
-	uint64_t entry_id;
+	uint64_t entry_id = 0;
 
 	if (dev == NULL) {
 		return NULL;
@@ -905,7 +905,7 @@ static int set_report(hid_device *dev, IOHIDReportType type, const unsigned char
 	                           data_to_send, length_to_send);
 
 	if (res == kIOReturnSuccess) {
-		return length;
+		return (int) length;
 	}
 
 	return -1;
@@ -939,7 +939,7 @@ static int get_report(hid_device *dev, IOHIDReportType type, unsigned char *data
 		if (report_id == 0x0) { /* 0 report number still present at the beginning */
 			report_length++;
 		}
-		return report_length;
+		return (int) report_length;
 	}
 
 	return -1;
@@ -961,7 +961,7 @@ static int return_data(hid_device *dev, unsigned char *data, size_t length)
 	dev->input_reports = rpt->next;
 	free(rpt->data);
 	free(rpt);
-	return len;
+	return (int) len;
 }
 
 static int cond_wait(const hid_device *dev, pthread_cond_t *cond, pthread_mutex_t *mutex)