driver/printf: disable preemption in dtrace_vprintf
mutex: use this_cpu instead of smp_processor_id() (fix for 805244f80a6a61b)
dtrace_gethrtime: enable/disable preemtion for native_sched_clock_ptr

Because kernel complain about using smp_processor_id() there.
dtrace_xcall1: don't use smp_processor_id()
dtrace_xcall2: don't use smp_processor_id()
replace cpu_get_id() macro by inline function, without smp_processor_id()