Fix warning about incompatible pointers in synctex parser

core/synctex/synctex_parser.c

@@ -4144,7 +4144,7 @@ typedef int (*synctex_fprintf_t)(void *, const char * , ...); /*  print formatte
 #   define SYNCTEX_BITS_PER_BYTE 8
 
 struct __synctex_updater_t {
-    void *file;                 /*  the foo.synctex or foo.synctex.gz I/O identifier  */
+    struct gzFile_s *file;                 /*  the foo.synctex or foo.synctex.gz I/O identifier  */
 	synctex_fprintf_t fprintf;  /*  either fprintf or gzprintf */
 	int length;                 /*  the number of chars appended */
     struct _flags {