pp.c: Call subroutine instead of repeat code

pp.c: Call subroutine instead of repeat code

Now that toUPPER_utf8() has the intelligence to skip going out to
swashes for Latin1 code points, it's not so critical to bypass calling
it for these (for speed).  It simplifies things not to have the
intelligence repeated.  There is the additional overhead of two function
calls (minus the branches saved), but these could be avoided if it comes
down to it by making them in-line.