KVM: PPC: Remove extra get_page() to fix page refcount leak

Don't manually do get_page() when patching dcbz, as gfn_to_page() gifts
the caller a reference.  I.e. doing get_page() will leak the page due to
not putting all references.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-74-seanjc@google.com>

Author: sean-jc

arch/powerpc/kvm/book3s_pr.c

@@ -652,7 +652,6 @@ static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 	hpage_offset &= ~0xFFFULL;
 	hpage_offset /= 4;
 
-	get_page(hpage);
 	page = kmap_atomic(hpage);
 
 	/* patch dcbz into reserved instruction, so we trap */