perf session: Remove impossible condition check

The 'size' cannot be 0 because it was set to 8 on the above line in case
it was 0 and never changed.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1325000151-4463-1-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -1015,8 +1015,7 @@ static int __perf_session__process_pipe_events(struct perf_session *self,
 		}
 	}
 
-	if (size == 0 ||
-	    (skip = perf_session__process_event(self, &event, tool, head)) < 0) {
+	if ((skip = perf_session__process_event(self, &event, tool, head)) < 0) {
 		dump_printf("%#" PRIx64 " [%#x]: skipping unknown header type: %d\n",
 			    head, event.header.size, event.header.type);
 		/*