Ignore vmlinux build-id when user gives offline vmlinux if the command
does not affect running kernel.

perf-probe has several actions some of them does not change the running
kernel, like --lines, --vars, and --funcs.

e.g.
  -----
  $ ./perf probe -k ./vmlinux-arm -V do_sys_open:14
  Available variables at do_sys_open:14
          @<do_sys_open+202>
                  char*   filename
                  int     dfd
                  int     fd
                  int     flags
                  struct filename*        tmp
                  struct open_flags       op
                  umode_t mode
  -----
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147222347320.5088.2582658035296667520.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>