kmemcheck: remove useless check

This check is a left-over from ancient times. We now have the equivalent
check much earlier in both the page fault handler and the debug trap
handler (the calls to kmemcheck_active()).

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

arch/x86/mm/kmemcheck/kmemcheck.c

@@ -225,9 +225,6 @@ void kmemcheck_hide(struct pt_regs *regs)
 
 	BUG_ON(!irqs_disabled());
 
-	if (data->balance == 0)
-		return;
-
 	if (unlikely(data->balance != 1)) {
 		kmemcheck_show_all();
 		kmemcheck_error_save_bug(regs);