cleanup: Remove unnecessary info message for dbus matcher

Remove the needUpdate message once it has been set to true.
This is to reduce the amount of spam generated by this daemon.

Change-Id: Id21675e2cbca89ebb35eb29af053bfd9d917b14a
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/healthMonitor.cpp b/healthMonitor.cpp
index be62c3a..c87e4f0 100644
--- a/healthMonitor.cpp
+++ b/healthMonitor.cpp
@@ -627,7 +627,7 @@
             [conn](sdbusplus::message::message& msg) {
                 sdbusplus::message::object_path o;
                 msg.read(o);
-                if (o.str == phosphor::health::BMCActivationPath)
+                if (!needUpdate && o.str == phosphor::health::BMCActivationPath)
                 {
                     info("should recreate sensors now");
                     needUpdate = true;