x86: last of trivial fault_32|64.c unification

Comments, indentation, printk format.

Uses task_pid_nr() on X86_64 now, but this is always defined
to task->pid.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>