KVM: x86: MMU: make array audit_point_name static

The array audit_point_name is local to the source and does not need to
be in global scope, so make it static.

Cleans up sparse warning:
arch/x86/kvm/mmu_audit.c:22:12: warning: symbol 'audit_point_name' was
not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu_audit.c

@@ -19,7 +19,7 @@
 
 #include <linux/ratelimit.h>
 
-char const *audit_point_name[] = {
+static char const *audit_point_name[] = {
 	"pre page fault",
 	"post page fault",
 	"pre pte write",