Moved typedef to be inline with the struct for gpsd_unit and to match other structs in file

ntpd/refclock_gpsd.c

@@ -239,10 +239,8 @@ struct refclock refclock_gpsdjson = {
 /* =====================================================================
  * our local clock unit and data
  */
-struct gpsd_unit;
-typedef struct gpsd_unit gpsd_unitT;
 
-struct gpsd_unit {
+typedef struct gpsd_unit {
 	/* links for sharing between master/slave units */
 	gpsd_unitT *next_unit;
 	size_t      refcount;
@@ -318,7 +316,7 @@ struct gpsd_unit {
 	/* record assemby buffer and saved length */
 	int  buflen;
 	char buffer[MAX_PDU_LEN];
-};
+} gpsd_unitT;
 
 /* =====================================================================
  * static local helpers forward decls