tracing/filters: NIL-terminate user input filter
tracing/filters: NIL-terminate user input filter

Make sure messages from user space are NIL-terminated strings,
otherwise we could dump random memory while reading filter file.

Try this:
 # echo 'parent_comm ==' > events/sched/sched_process_fork/filter
 # cat events/sched/sched_process_fork/filter
 parent_comm == �

Signed-off-by: Li Zefan <5dc16b054e85ffba6c8d314d8e55ae95dcab12a5@cn.fujitsu.com>
Acked-by: Tom Zanussi <ca42f6846873622f2a6dc51a5106ba83ffbdaf95@gmail.com>
Acked-by: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Cc: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
LKML-Reference: <94f95a811bc4e3ccce4e15576f7e2a003c3b61a4@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas