tracing: add run-time field descriptions for event filtering, kfree fix
tracing: add run-time field descriptions for event filtering, kfree fix

Impact: fix potential kfree of random data in (rare) failure path

Zero-initialize the field structure.

Reported-by: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Cc: Tom Zanussi <ca42f6846873622f2a6dc51a5106ba83ffbdaf95@gmail.com>
LKML-Reference: <858401835ab83004c10d09d0f3bead7bf8d1658c@charm-linux>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

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