perf trace: Fix build when DWARF unwind isn't available

The variable is initialized and then conditionally set to a different
value, but not used when DWARF unwinding is not available, bummer, write
1000 times: "Run make -C tools/perf build-test"...

  builtin-trace.c: In function ‘cmd_trace’:
  builtin-trace.c:3112:6: error: variable ‘max_stack_user_set’ set but not
  used [-Werror=unused-but-set-variable]
    bool max_stack_user_set = true;
        ^
  cc1: all warnings being treated as err

Fix it by marking it as __maybe_unused.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Milian Wolff <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Fixes: 056149932602 ("perf trace: Make --(min,max}-stack imply "--call-graph dwarf"")
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions