perf trace beauty fcntl: Do not suppress 'cmd' when zero, should be DUPFD

Before:

 77059.513 ( 0.005 ms): bash/6649 fcntl(fd: 1</dev/pts/12>, arg: 10) = 10</dev/pts/12>

After:

 77059.513 ( 0.005 ms): bash/6649 fcntl(fd: 1</dev/pts/12>, cmd: DUPFD, arg: 10) = 10</dev/pts/12>

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-woois88uwcr4xu38xx1ihiwo@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>