perf trace: Initial beautifier for ioctl's 'cmd' arg

 [root@zoo linux]# trace -e ioctl | grep -v "cmd: 0x" | head -10
      0.386 ( 0.001 ms): trace/1602 ioctl(fd: 1<pipe:[127057]>, cmd: TCGETS, arg: 0x7fff59fcb4d0          ) = -1 ENOTTY Inappropriate ioctl for device
   1459.368 ( 0.002 ms): inotify_reader/10352 ioctl(fd: 18<anon_inode:inotify>, cmd: FIONREAD, arg: 0x7fb835228bcc  ) = 0
   1463.586 ( 0.002 ms): inotify_reader/10352 ioctl(fd: 18<anon_inode:inotify>, cmd: FIONREAD, arg: 0x7fb835228bcc  ) = 0
   1463.611 ( 0.002 ms): inotify_reader/10352 ioctl(fd: 18<anon_inode:inotify>, cmd: FIONREAD, arg: 0x7fb835228bcc  ) = 0
   3740.526 ( 0.002 ms): awk/1612 ioctl(fd: 1<pipe:[128265]>, cmd: TCGETS, arg: 0x7fff4d166b90          ) = -1 ENOTTY Inappropriate ioctl for device
   3740.704 ( 0.001 ms): awk/1612 ioctl(fd: 3</proc/meminfo>, cmd: TCGETS, arg: 0x7fff4d1669a0          ) = -1 ENOTTY Inappropriate ioctl for device
   3742.550 ( 0.002 ms): ps/1614 ioctl(fd: 1<pipe:[128266]>, cmd: TIOCGWINSZ, arg: 0x7fff591762b0      ) = -1 ENOTTY Inappropriate ioctl for device
   3742.555 ( 0.003 ms): ps/1614 ioctl(fd: 2<socket:[19550]>, cmd: TIOCGWINSZ, arg: 0x7fff591762b0     ) = -1 ENOTTY Inappropriate ioctl for device
   3742.558 ( 0.002 ms): ps/1614 ioctl(cmd: TIOCGWINSZ, arg: 0x7fff591762b0                            ) = -1 ENOTTY Inappropriate ioctl for device
   3742.572 ( 0.002 ms): ps/1614 ioctl(fd: 1<pipe:[128266]>, cmd: TCGETS, arg: 0x7fff59176220          ) = -1 ENOTTY Inappropriate ioctl for device
 [root@zoo linux]#

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-afajwap3mr60dfl4qpdl1pxn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>