remove "Not enough samples" log to journal

Noticed on a few systems that this is filling up the journal. Not sure
why the "debug" logs are even making it to the journal via lg2 but this
one needs to go if debug is going always be going to the journal by
default.

Change-Id: I6667552186c38bd38a2105c7cbd8aeb0aa56f3e6
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/health_metric.cpp b/health_metric.cpp
index 2887766..ad74597 100644
--- a/health_metric.cpp
+++ b/health_metric.cpp
@@ -236,7 +236,6 @@
     if (history.size() < config.windowSize)
     {
         // Wait for the metric to have enough samples to calculate average
-        debug("Not enough samples to calculate average");
         return;
     }