Fix internal error of boot override properties

Multihost system doesn't have host0 object and we do not plan to
support this unnecessary feature at the moment. Do not raise an
internal error to avoid causing system URI failures with a 500
return code.

Tested on yosemite4:
- Verified that no internal error occurs during the boot override
  process.

Change-Id: I4d13db3c77be2ee709884cde813df9593b575530
Signed-off-by: Allen Wang <Allen_Wang@quantatw.com>
diff --git a/redfish-core/lib/systems.hpp b/redfish-core/lib/systems.hpp
index e4f02cc..832c644 100644
--- a/redfish-core/lib/systems.hpp
+++ b/redfish-core/lib/systems.hpp
@@ -996,12 +996,14 @@
                     const std::string& bootSourceStr) {
             if (ec)
             {
-                if (ec.value() == boost::asio::error::host_unreachable)
+                // Service not available, no error, just don't return
+                // Boot Override Source information
+                if (ec.value() != EBADR &&
+                    ec.value() != boost::asio::error::host_unreachable)
                 {
-                    return;
+                    BMCWEB_LOG_ERROR("D-Bus response error: {}", ec);
+                    messages::internalError(asyncResp->res);
                 }
-                BMCWEB_LOG_ERROR("DBUS response error {}", ec);
-                messages::internalError(asyncResp->res);
                 return;
             }
 
@@ -1087,12 +1089,14 @@
                     const bool bootOverrideEnable) {
             if (ec)
             {
-                if (ec.value() == boost::asio::error::host_unreachable)
+                // Service not available, no error, just don't return
+                // Boot Override Enable information
+                if (ec.value() != EBADR &&
+                    ec.value() != boost::asio::error::host_unreachable)
                 {
-                    return;
+                    BMCWEB_LOG_ERROR("D-Bus response error: {}", ec);
+                    messages::internalError(asyncResp->res);
                 }
-                BMCWEB_LOG_ERROR("DBUS response error {}", ec);
-                messages::internalError(asyncResp->res);
                 return;
             }