psu-ng: Clear the additionalData each loop

In the analyze() function of the psuManager, clear out the
additionalData each time we loop to the next power supply. If we do not
do this, and multiple power supplies encounter faults, call out data for
a different power supply may end up being added to the wrong error(s).

Tested:
    Simulated triple power supply fault while chassis power on.
    Verified correct call out details, extras noted earlier not there.
    Faults: psu0 comm fault, psu1 missing, psu3 UV.

Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
Change-Id: I1d22dda450a08abc59b95c9de9c6750ac78a439f
diff --git a/phosphor-power-supply/psu_manager.cpp b/phosphor-power-supply/psu_manager.cpp
index 378c0c1..4cfa801 100644
--- a/phosphor-power-supply/psu_manager.cpp
+++ b/phosphor-power-supply/psu_manager.cpp
@@ -377,6 +377,7 @@
 
         for (auto& psu : psus)
         {
+            additionalData.clear();
             // TODO: Fault priorities #918
             if (!psu->isFaultLogged() && !psu->isPresent())
             {