perf report: Do not drop last inlined frame

The very last inlined frame, i.e. the one furthest away from the
non-inlined frame, was silently dropped. This is apparent when
comparing the output of `perf script` and `addr2line`:

~~~~~~
  $ perf script --inline
  ...
  a.out 26722 80836.309329:      72425 cycles:
                     21561 __hypot_finite (/usr/lib/libm-2.25.so)
                      ace3 hypot (/usr/lib/libm-2.25.so)
                       a4a main (a.out)
                           std::abs<double>
                           std::_Norm_helper<true>::_S_do_it<double>
                           std::norm<double>
                           main
                     20510 __libc_start_main (/usr/lib/libc-2.25.so)
                       bd9 _start (a.out)

  $ addr2line -a -f -i -e /tmp/a.out a4a | c++filt
  0x0000000000000a4a
  std::__complex_abs(doublecomplex )
  /usr/include/c++/6.3.1/complex:589
  double std::abs<double>(std::complex<double> const&)
  /usr/include/c++/6.3.1/complex:597
  double std::_Norm_helper<true>::_S_do_it<double>(std::complex<double> const&)
  /usr/include/c++/6.3.1/complex:654
  double std::norm<double>(std::complex<double> const&)
  /usr/include/c++/6.3.1/complex:664
  main
  /tmp/inlining.cpp:14
~~~~~

Note how `std::__complex_abs` is missing from the `perf script`
output. This is similarly showing up in `perf report`. The patch
here fixes this issue, and the output becomes:

~~~~~
  a.out 26722 80836.309329:      72425 cycles:
                     21561 __hypot_finite (/usr/lib/libm-2.25.so)
                      ace3 hypot (/usr/lib/libm-2.25.so)
                       a4a main (a.out)
                           std::__complex_abs
                           std::abs<double>
                           std::_Norm_helper<true>::_S_do_it<double>
                           std::norm<double>
                           main
                     20510 __libc_start_main (/usr/lib/libc-2.25.so)
                       bd9 _start (a.out)
~~~~~

Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-7-namhyung@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>