Fix PATCH on hypervisor IPv4Addresses

Currently Patch on ipv4addresses overrides values because of
missing return statement.

Tested By:

PATCH -d '{"IPv4Addresses": [null]}' https://${bmc_ip}/redfish/v1/Systems/hypervisor/EthernetInterfaces/eth0

Signed-off-by: Ravi Teja <raviteja28031990@gmail.com>
Change-Id: I1839572e635f137a93c777468a6cc6cc18059f4e
diff --git a/redfish-core/lib/hypervisor_system.hpp b/redfish-core/lib/hypervisor_system.hpp
index 79a89fa..8aa9a44 100644
--- a/redfish-core/lib/hypervisor_system.hpp
+++ b/redfish-core/lib/hypervisor_system.hpp
@@ -880,6 +880,7 @@
             if (ipv4Addresses)
             {
                 messages::propertyNotWritable(asyncResp->res, "IPv4Addresses");
+                return;
             }
 
             if (dhcpv4)