Fix typo.

counter.c/main.c

@@ -1,7 +1,7 @@
 #include <stdlib.h>
 #include "counter.h"
 
-void read_ulong(uint_t *r) {
+void read_ulong(unsigned long *r) {
   *r = 0;
 
   for (unsigned long i = 0; i < sizeof(unsigned long); i++)