taint: add explicit flag to show whether lock dep is still OK.

Fix up all callers as they were before, with make one change: an
unsigned module taints the kernel, but doesn't turn off lockdep.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

arch/x86/kernel/cpu/mcheck/mce.c

@@ -1085,7 +1085,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 		/*
 		 * Set taint even when machine check was not enabled.
 		 */
-		add_taint(TAINT_MACHINE_CHECK);
+		add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
 
 		severity = mce_severity(&m, cfg->tolerant, NULL);
 

arch/x86/kernel/cpu/mcheck/p5.c

@@ -33,7 +33,7 @@ static void pentium_machine_check(struct pt_regs *regs, long error_code)
 			smp_processor_id());
 	}
 
-	add_taint(TAINT_MACHINE_CHECK);
+	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
 }
 
 /* Set up machine check reporting for processors with Intel style MCE: */

arch/x86/kernel/cpu/mcheck/winchip.c

@@ -15,7 +15,7 @@
 static void winchip_machine_check(struct pt_regs *regs, long error_code)
 {
 	printk(KERN_EMERG "CPU0: Machine Check Exception.\n");
-	add_taint(TAINT_MACHINE_CHECK);
+	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
 }
 
 /* Set up machine check reporting on the Winchip C6 series */