tracing/filters: don't remove old filters when failed to write subsys->filter
tracing/filters: don't remove old filters when failed to write subsys->filter

If writing subsys->filter returns EINVAL or ENOSPC, the original
filters in subsys/ and subsys/events/ will be removed. This is
definitely wrong.

[ Impact: fix filter setting semantics on error condition ]

Signed-off-by: Li Zefan <5dc16b054e85ffba6c8d314d8e55ae95dcab12a5@cn.fujitsu.com>
Cc: Tom Zanussi <ca42f6846873622f2a6dc51a5106ba83ffbdaf95@gmail.com>
Cc: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
Cc: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
LKML-Reference: <9dc751135e7d42caf3dbc820a3ba393edeaccc26@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

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