change int to unsigned short

src/custom_sem.c

@@ -1,6 +1,7 @@
 #include <sys/sem.h>
-
+#include <sys/stat.h>
 #include <custom_sem.h>
+#include <structures.h>
 #include <errExit.h>
 
 void semOp(int semid, short sem_num, short sem_op) {
@@ -17,7 +18,7 @@ int getSemid(){
         errExit("semget", "getSemid");
     }
 
-    int val[] = {0, 0};
+    unsigned short val[] = {0, 0};
     union semun arg;
     arg.array = val;