Add UNUSED tag to system call function skeletons w/ S.

src/userprog/syscall.c

@@ -105,76 +105,76 @@ exit (int status UNUSED)
 }
 
 static pid_t
-exec (const char *cmd_line)
+exec (const char *cmd_line UNUSED)
 {
   //TODO
   return 0;
 }
 
 static int
-wait (pid_t pid)
+wait (pid_t pid UNUSED)
 {
   //TODO
   return 0;
 }
 
 static bool
-file_create (const char *file, unsigned initial_size)
+file_create (const char *file UNUSED, unsigned initial_size UNUSED)
 {
   //TODO
   return 0;
 }
 
 static bool
-file_remove (const char *file)
+file_remove (const char *file UNUSED)
 {
   //TODO
   return 0;
 }
 
 static int
-open (const char *file)
+open (const char *file UNUSED)
 {
   //TODO
   return 0;
 }
 
 static int
-filesize (int fd)
+filesize (int fd UNUSED)
 {
   //TODO
   return 0;
 }
 
 static int
-read (int fd, void *buffer, unsigned size)
+read (int fd UNUSED, void *buffer UNUSED, unsigned size UNUSED)
 {
   //TODO
   return 0;
 }
 
 static int
-write (int fd, const void *buffer, unsigned size)
+write (int fd UNUSED, const void *buffer UNUSED, unsigned size UNUSED)
 {
   //TODO
   return 0;
 }
 
 static void
-seek (int fd, unsigned position)
+seek (int fd UNUSED, unsigned position UNUSED)
 {
   //TODO
 }
 
 static unsigned
-tell (int fd)
+tell (int fd UNUSED)
 {
   //TODO
   return 0;
 }
 
 static void
-close (int fd)
+close (int fd UNUSED)
 {
   //TODO
 }