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

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 <[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]>