x86: notsc is ignored on common configurations

notsc is ignored in 32-bit kernels if CONFIG_X86_TSC is on.. which is
bad, fix it.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/tsc_32.c

@@ -28,7 +28,8 @@ EXPORT_SYMBOL_GPL(tsc_khz);
 static int __init tsc_setup(char *str)
 {
 	printk(KERN_WARNING "notsc: Kernel compiled with CONFIG_X86_TSC, "
-				"cannot disable TSC.\n");
+				"cannot disable TSC completely.\n");
+	mark_tsc_unstable("user disabled TSC");
 	return 1;
 }
 #else