sim/ppc: fix warnings related to printf format strings

This commit is a follow on to:

  commit 182421c9
  Date:   Tue Oct 11 15:02:08 2022 +0100

      sim/ppc: fixes for arguments to printf style functions

where commit 182421c9 addressed issues with printf format
arguments that were causing the compiler to give an error, this commit
addresses issues that caused the compiler to emit a warning.

This commit is mostly either changing the format string to match the
argument, or in some cases, excess, unused arguments are removed.