tracing/kprobes: unregister_trace_probe needs to be called under mutex
tracing/kprobes: unregister_trace_probe needs to be called under mutex

Comment in unregister_trace_probe() says probe_lock will be held when it
gets called. However there is a case where it might called without the
probe_lock being held. Also since we are traversing the probe_list and
deleting an element from the probe_list, probe_lock should be held.

This was first pointed in uprobes traceevent review by Frederic
Weisbecker here.  (http://lkml.org/lkml/2010/5/12/106)

Cc: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>
Cc: Masami Hiramatsu <60fcdccfd958d359debfe6e6e7417cd7f1aaa9e3@hitachi.com>
Acked-by: Masami Hiramatsu <60fcdccfd958d359debfe6e6e7417cd7f1aaa9e3@hitachi.com>
Acked-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
LKML-Reference: <64d4a97dc3528ec18389c3bc7fd572ac1bd67850@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <1f69195f6d934d4caf5816234bde319316df237e@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

KristFoundation/Programs,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,TeamVee-Kanas/android_kernel_samsung_kanas