perf tests: Stop reading if objdump output crossed sections

perf tests: Stop reading if objdump output crossed sections

objdump output can span across multiple sections:

  Disassembly of section .text:
    0000000000000008 <crc32c+0x8>:
       8:       48 89 e5                mov    %rsp,%rbp
       b:       53                      push   %rbx
       c:       8b 01                   mov    (%rcx),%eax
    <snip>
      6b:       90                      nop

  Disassembly of section .init.text:
    0000000000000008 <init_module+0x8>:
       8:       00 00                   add    %al,(%rax)
       a:       00 00                   add    %al,(%rax)
       c:       48 89 e5

Stop further reading if an address starts going backwards, assuming we
crossed sections.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/9d1ea95e5f9884fdff1be6f761a2feabef37412c.1441181335.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>