securityeval: Pre-initialize counter array

It *is* initialized, but some compilers fail to see that and
print a scary warning.

Change-Id: I2f92767f6c0e5186112e814c160841523dbdac5e
Reviewed-by: Stepan Salenikovich <stepan.salenikovich@savoirfairelinux.com>

src/securityevaluationmodel.cpp

@@ -724,7 +724,7 @@ void SecurityEvaluationModelPrivate::updateReal()
    typedef SecurityEvaluationModel::Severity      Severity     ;
    typedef SecurityEvaluationModel::SecurityLevel SecurityLevel;
 
-   int countCache[enum_class_size<SecurityEvaluationModel::Severity>()];
+   int countCache[enum_class_size<SecurityEvaluationModel::Severity>()] = {};
 
    //Reset the counter
    for (const Severity s : EnumIterator<Severity>()) {