tools lib traceevent: Check string is really printable
tools lib traceevent: Check string is really printable

When libtraceevent parses format fields, it assumes that array of 1 byte
is string but it's not always true. The kvm_emulate_insn contains 15 u8
array of insn that contains (binary) instructions. Thus when it's
printed, it'll have broken output like below:

  kvm_emulate_insn:     [FAILED TO PARSE] rip=3238197797 csbase=0 len=2 \
  insn=<89>P^]<B4>& flags=5 failed=0

With this patch:

  kvm_emulate_insn:     [FAILED TO PARSE] rip=3238197797 csbase=0 len=2 \
  insn=ARRAY[89, 10, 5d, c3, 8d, b4, 26, 00, 00, 00, 00, 55, 89, e5, 3e] flags=5 failed=0

Suggested-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
Signed-off-by: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org>
Cc: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Cc: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@kernel.org>
Cc: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Cc: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
Link: http://lkml.kernel.org/r/1340352615-20737-2-git-send-email-5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

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