ANDROID: KVM: arm64: Do not pkvm_init_devices() when no registered devices

When registered_devices_nr is 0, the donation would fail leading to a
wrong -EPERM error.

Bug: 357781595
Bug: 384432312
Change-Id: Ib1e057387a60e47b41750fdfee85f5b440b7a81e
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

arch/arm64/kvm/hyp/nvhe/device/device.c

@@ -31,6 +31,9 @@ int pkvm_init_devices(void)
 	size_t dev_sz;
 	int ret;
 
+	if (!registered_devices_nr)
+		return 0;
+
 	registered_devices = kern_hyp_va(registered_devices);
 	dev_sz = PAGE_ALIGN(size_mul(sizeof(struct pkvm_device),
 				     registered_devices_nr));