(fwRenderOgre): Differentiate std::isInf from the macro isInf of math.h

What does this MR do?

We need to differenciate std::isInf from the macro isInf of math.h.

How to test it?

Try to build Sight.

Some results

Sight has to be built without errors.

Associated Issues/Merge Requests

• Issues
  • Closes #360 (closed)