AuxDataSpan: suppress cppcheck false positive

Suppress cppcheck warning.

Bug report: https://sourceforge.net/p/cppcheck/discussion/general/thread/9edfb407a9/

cc @ssnyder

Control/AthContainersInterfaces/AthContainersInterfaces/AuxDataSpan.h

@@ -42,6 +42,7 @@ struct AuxDataSpanBase
    * @param the_beg The start of the variable's vector.
    * @param the_size The length of the variable's vector.
    */
+  // cppcheck-suppress uninitMemberVar; false positive
   AuxDataSpanBase (void* the_beg = 0, size_t the_size = 0)
     : beg(the_beg), size(the_size)
   {