kprobes: Reuse unused kprobe
kprobes: Reuse unused kprobe

Reuse unused (waiting for unoptimizing and no user handler)
kprobe on given address instead of returning -EBUSY for
registering a new kprobe.

Signed-off-by: Masami Hiramatsu <60fcdccfd958d359debfe6e6e7417cd7f1aaa9e3@hitachi.com>
Cc: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>
Cc: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Cc: Ananth N Mavinakayanahalli <7dc108d19a2513f6455353af182b9e4d3b794ec9@in.ibm.com>
Cc: Jason Baron <af9bd1db766a43cb09b647251c97dbddcd2e59dc@redhat.com>
Cc: Mathieu Desnoyers <007bef6a47fb57dff675bfa1b0b798b4bdfbfc25@efficios.com>
Cc: 3c8b2a59b7e748a88c5b8589b841c882ca47ab8c@sdl.hitachi.co.jp
LKML-Reference: <c8a138f8b71009838344bd23fb262aa09793f13d@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

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