x86: don't wank with magical size in __copy_in_user()

... especially since copy_in_user() doesn't

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/x86/lib/usercopy_64.c

@@ -54,15 +54,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
 }
 EXPORT_SYMBOL(clear_user);
 
-unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len)
-{
-	if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { 
-		return copy_user_generic((__force void *)to, (__force void *)from, len);
-	} 
-	return len;		
-}
-EXPORT_SYMBOL(copy_in_user);
-
 /*
  * Try to copy last bytes and clear the rest if needed.
  * Since protection fault in copy_from/to_user is not a normal situation,