KVM: x86: fix KVM_SET_XCRS loop

The loop was always using 0 as the index.  This means that
any rubbish after the first element of the array went undetected.
It seems reasonable to assume that no KVM userspace did that.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2961549..6d16fc5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3064,9 +3064,9 @@
 
 	for (i = 0; i < guest_xcrs->nr_xcrs; i++)
 		/* Only support XCR0 currently */
-		if (guest_xcrs->xcrs[0].xcr == XCR_XFEATURE_ENABLED_MASK) {
+		if (guest_xcrs->xcrs[i].xcr == XCR_XFEATURE_ENABLED_MASK) {
 			r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
-				guest_xcrs->xcrs[0].value);
+				guest_xcrs->xcrs[i].value);
 			break;
 		}
 	if (r)