If event_read_fields failed in the middle, each member of
struct format_field should be freed also.

Cc: Borislav Petkov <bp@alien8.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337740619-27925-11-git-send-email-namhyung.kim@lge.comSigned-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>