advfs: Remove ms_assert.h and head for native kernel asserts
advfs MS_SMP_ASSERT -> KASSERT
advfs: Stop including ms_assert.h
advfs: ucred -> uucred and add missing include <sys/ucred.h>
advfs: Enhance const-correctness of ms_*printf functions
advfs: Add missing header bs_access.h
advfs: Enhance const-correctness of _ms_free()
advfs: fix 'label at end of compound statement'
advfs: Stop using the last unused parameter of dyn_hashtable_init