perf top: Use __fallthrough

The implicit fall through case label here is intended, so let us inform
that to gcc >= 7:

    CC       /tmp/build/perf/builtin-top.o
  builtin-top.c: In function 'display_thread':
  builtin-top.c:644:7: error: this statement may fall through [-Werror=implicit-fallthrough=]
      if (errno == EINTR)
         ^
  builtin-top.c:647:3: note: here
     default:
   ^~~~~~~

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions