KVM: MMU: fix bogus alloc_mmu_pages assignment

(cherry picked from commit b90c062c)

Remove the bogus n_free_mmu_pages assignment from alloc_mmu_pages.

It breaks accounting of mmu pages, since n_free_mmu_pages is modified
but the real number of pages remains the same.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/kvm/mmu.c

@@ -2713,14 +2713,6 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
 
 	ASSERT(vcpu);
 
-	spin_lock(&vcpu->kvm->mmu_lock);
-	if (vcpu->kvm->arch.n_requested_mmu_pages)
-		vcpu->kvm->arch.n_free_mmu_pages =
-					vcpu->kvm->arch.n_requested_mmu_pages;
-	else
-		vcpu->kvm->arch.n_free_mmu_pages =
-					vcpu->kvm->arch.n_alloc_mmu_pages;
-	spin_unlock(&vcpu->kvm->mmu_lock);
 	/*
 	 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
 	 * Therefore we need to allocate shadow page tables in the first