KVM: Don't free new memslot if allocation of said memslot fails

The two implementations of kvm_arch_create_memslot() in x86 and PPC are
both good citizens and free up all local resources if creation fails.
Return immediately (via a superfluous goto) instead of calling
kvm_free_memslot().

Note, the call to kvm_free_memslot() is effectively an expensive nop in
this case as there are no resources to be freed.

No functional change intended.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/kvm_main.c

@@ -1089,7 +1089,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		new.userspace_addr = mem->userspace_addr;
 
 		if (kvm_arch_create_memslot(kvm, &new, npages))
-			goto out_free;
+			goto out;
 	}
 
 	/* Allocate page dirty bitmap if needed */