COMP: Const char * ternary operators

The following warning:
warning #3179: deprecated conversion of string literal to char* (should be const char*)

is issued when the first return item of a ternary operator is a "char *" and the
second return item is a  "const char *" because the effective temporary variable
will have the same type as the first element.

Change-Id: Ib065f114cae03752a90d119e864d76b44a751391
BUG: Derived test class missing required logic

The required logic for all dereived threaded metric classes
is that they must check if the derivative is requested before
atttempting to compute them.  During the refactoring for fixing
false sharing of variables, it is now possible that these
temporary variables do not exists and therefore can not be computed.

Change-Id: I0263cddecc69af22aeae66b05864ec8d6b88b70e
Merge topic 'RemoveFalseSharing'

e63ead9 BUG: Derived test class missing required logic
2f23cf2 COMP: Const char * ternary operators