ethernet_interface: Link local IPs are never DHCP

The concept of an interface having a link local IP is orthogonal to DHCP
vs static addressing and we should never be receiving a link local IP
over DHCP.

Change-Id: I80040054f8c9acad3d3d0afa12c5738b43957a4a
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/ethernet_interface.cpp b/ethernet_interface.cpp
index 94bfecd..e7da8ff 100644
--- a/ethernet_interface.cpp
+++ b/ethernet_interface.cpp
@@ -86,7 +86,7 @@
         {
             origin = IP::AddressOrigin::DHCP;
         }
-        else if (isLinkLocalIP(addr.ipaddress))
+        if (isLinkLocalIP(addr.ipaddress))
         {
             origin = IP::AddressOrigin::LinkLocal;
         }