NVMeSensorMain: Make early exits contiguous

This makes for a clear pattern of behaviour.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: Ie9b74e384d7a6a5c0c4a7a9d2466e2b292a33497
diff --git a/src/NVMeSensorMain.cpp b/src/NVMeSensorMain.cpp
index fe4fb5b..2e29eaf 100644
--- a/src/NVMeSensorMain.cpp
+++ b/src/NVMeSensorMain.cpp
@@ -167,6 +167,12 @@
             continue;
         }
 
+        std::optional<int> rootBus = deriveRootBus(busNumber);
+        if (!rootBus)
+        {
+            continue;
+        }
+
         std::vector<thresholds::Threshold> sensorThresholds;
         if (!parseThresholdsFromConfig(sensorData, sensorThresholds))
         {
@@ -174,12 +180,6 @@
                       << "\n";
         }
 
-        std::optional<int> rootBus = deriveRootBus(busNumber);
-        if (!rootBus)
-        {
-            continue;
-        }
-
         std::shared_ptr<NVMeSensor> sensorPtr = std::make_shared<NVMeSensor>(
             objectServer, io, dbusConnection, *sensorName,
             std::move(sensorThresholds), interfacePath, *busNumber);