tools strfilter: Use __fallthrough

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

  util/strfilter.c: In function 'strfilter_node__sprint':
  util/strfilter.c:270:6: error: this statement may fall through [-Werror=implicit-fallthrough=]
     if (len < 0)
        ^
  util/strfilter.c:272:2: note: here
    case '!':
    ^~~~
  cc1: all warnings being treated as errors

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-z2dpywg7u8fim000hjfbpyfm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/perf/util/strfilter.c b/tools/perf/util/strfilter.c
index bcae659b6546..efb53772e0ec 100644
--- a/tools/perf/util/strfilter.c
+++ b/tools/perf/util/strfilter.c
@@ -269,6 +269,7 @@ static int strfilter_node__sprint(struct strfilter_node *node, char *buf)
                 len = strfilter_node__sprint_pt(node->l, buf);
                 if (len < 0)
                         return len;
+                __fallthrough;
         case '!':
                 if (buf) {
                         *(buf + len++) = *node->p;