score: Add missing inline
score: Format
score: Fix warnings
score: Move NULL pointer check to order function

This helps to avoid untestable code for the normal SMP schedulers.
score: Make functions inline

These functions are used only via the function pointers in the generic
SMP scheduler implementation.  Provide them as static inline so that the
compiler can optimize more easily.
smptests/smpscheduler03: Test all SMP schedulers