tools lib traceevent: Fix cast from pointer to integer for 32 bit

Fixing the integer cast reported by the following warning:

 tools/lib/traceevent/event-parse.c:3488:14: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1344361396-7237-5-git-send-email-robert.richter@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>