cleanup: drop obsolete is_method_error checks

is_method_error is obsolete from sdbusplus.

Change-Id: Ia3fb76dd2f4a14eca51b3cfbcd50427b36d946b3
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/dbus/util.cpp b/dbus/util.cpp
index 3e3597b..733aff4 100644
--- a/dbus/util.cpp
+++ b/dbus/util.cpp
@@ -117,10 +117,7 @@
     try
     {
         auto msg = bus.call(critical);
-        if (!msg.is_method_error())
-        {
-            msg.read(criticalMap);
-        }
+        msg.read(criticalMap);
     }
     catch (sdbusplus::exception_t&)
     {