0024284: Some trivial warnings produced by ICC 14

Eliminated ICC 14 warnings:
# 82: storage class is not first (e.g. "int static f()"
# 2621: attribute "dllexport" does not apply here (e.g. "Standard_EXPORT typedef int qqint;")
# 2415: variable "..." of static storage duration was declared but never referenced
# 111: statement is unreachable (usually "break" after "return" in cycles)

src/Extrema/Extrema_ExtElCS.cxx

@@ -308,7 +308,6 @@ void Extrema_ExtElCS::Perform(const gp_Circ& C,
       mySqDist->SetValue(1, aDist * aDist);
     } else {
       Standard_Integer aNbExt   = anExtC.NbExt();
-      gp_Pnt           aCenter  = C.Location();
       Standard_Integer i;
       Standard_Integer aCurI    = 1;
       Standard_Real    aTolConf = Precision::Confusion();