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 <B.Steinbrink@gmx.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

@@ -614,6 +614,12 @@ int lapic_watchdog_init(unsigned nmi_hz)
 		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))) {