remove is_method_error call

An `is_method_error` is not appropriate after an sdbus `call` since
`call` will always throw an exception.  Remove the pointless call
and instead catch the exception.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I6ece20bca5a99da3b7a6f3b6aa55b22842f3b422
diff --git a/src/inventory_mac.cpp b/src/inventory_mac.cpp
index 8d38c37..67e8dff 100644
--- a/src/inventory_mac.cpp
+++ b/src/inventory_mac.cpp
@@ -91,12 +91,17 @@
 
     mapperCall.append(invRoot, depth, interfaces);
 
-    auto mapperReply = bus.call(mapperCall);
-    if (mapperReply.is_method_error())
-    {
-        lg2::error("Error in mapper call");
-        elog<InternalFailure>();
-    }
+    auto mapperReply = [&]() {
+        try
+        {
+            return bus.call(mapperCall);
+        }
+        catch (const sdbusplus::exception::SdBusError& e)
+        {
+            lg2::error("Error in mapper call");
+            elog<InternalFailure>();
+        }
+    }();
 
     ObjectTree objectTree;
     mapperReply.read(objectTree);
@@ -145,14 +150,19 @@
 
     method.append(invNetworkIntf, "MACAddress");
 
-    auto reply = bus.call(method);
-    if (reply.is_method_error())
-    {
-        lg2::error(
-            "Failed to get MACAddress for path {DBUS_PATH} interface {DBUS_INTF}",
-            "DBUS_PATH", objPath, "DBUS_INTF", invNetworkIntf);
-        elog<InternalFailure>();
-    }
+    auto reply = [&]() {
+        try
+        {
+            return bus.call(method);
+        }
+        catch (const sdbusplus::exception::SdBusError& e)
+        {
+            lg2::error(
+                "Failed to get MACAddress for path {DBUS_PATH} interface {DBUS_INTF}",
+                "DBUS_PATH", objPath, "DBUS_INTF", invNetworkIntf);
+            elog<InternalFailure>();
+        }
+    }();
 
     std::variant<std::string> value;
     reply.read(value);