i386: fix NMI watchdog not reserving its MSRs

At system boot time, the NMI watchdog no longer reserved its MSRs, allowing
other subsystems to mess with them. Fix that.

Signed-off-by: Björn Steinbrink <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/i386/kernel/cpu/perfctr-watchdog.c

···
 		probe_nmi_watchdog();
 		if (!wd_ops)
 			return -1;
+
+		if (!wd_ops->reserve()) {
+			printk(KERN_ERR
+				"NMI watchdog: cannot reserve perfctrs\n");
+			return -1;
+		}
 	}
 
 	if (!(wd_ops->setup(nmi_hz))) {