Fix Bug in fd_get_file declaration use open_file instead of file, w/ E

src/userprog/syscall.c

@@ -44,6 +44,7 @@ static void syscall_seek (int fd, unsigned position);
 static unsigned syscall_tell (int fd);
 static void syscall_close (int fd);
 
+static struct open_file *fd_get_file (int fd);
 static void *validate_user_pointer (const void *ptr, size_t size);
 
 /* A struct defining a syscall_function pointer along with its arity. */
@@ -283,7 +284,7 @@ fd_less (const struct hash_elem *a_, const struct hash_elem *b_,
 
 /* Gets a file from its descriptor (FD number). If there is no file with the fd
    FD it returns NULL. */
-static struct file *
+static struct open_file *
 fd_get_file (int fd)
 {
   /* We have to set up a fake open_file in order to be able to search the hash
@@ -291,10 +292,10 @@ fd_get_file (int fd)
   struct open_file *fake_file_info;
   fake_file_info->fd = fd;
 
-  struct file *file
-    = hash_find (thread_current ()->open_files, fake_file_info->elem);
+  struct hash_elem *e
+    = hash_find (&thread_current ()->open_files, &fake_file_info->elem);
 
-  return file;
+  return hash_entry (e, struct open_file, elem);
 }
 
 /* Validates if a block of memory starting at PTR and of size SIZE bytes is