KVM: Fix vmx I/O bitmap initialization on highmem systems

kunmap() expects a struct page, not a virtual address.  Fixes an oops loading
kvm-intel.ko on i386 with CONFIG_HIGHMEM.

Thanks to Michael Ivanov <deruhu@peterstar.ru> for reporting.

Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index e39ebe0..34171d9 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -2274,11 +2274,11 @@
 	iova = kmap(vmx_io_bitmap_a);
 	memset(iova, 0xff, PAGE_SIZE);
 	clear_bit(0x80, iova);
-	kunmap(iova);
+	kunmap(vmx_io_bitmap_a);
 
 	iova = kmap(vmx_io_bitmap_b);
 	memset(iova, 0xff, PAGE_SIZE);
-	kunmap(iova);
+	kunmap(vmx_io_bitmap_b);
 
 	r = kvm_init_arch(&vmx_arch_ops, THIS_MODULE);
 	if (r)