tools lib traceevent: Avoid comparisions between signed/unsigned

Fixing this warning-as-error on f14 32-bit:

  tools/lib/traceevent/event-parse.c:5564:17: error: comparison between signed and unsigned integer expressions
  tools/lib/traceevent/event-parse.c:5586:17: error: comparison between signed and unsigned integer expressions

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.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>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-stmix8hy4nu5ervpynn8yj2z@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/event-parse.c

@@ -5561,7 +5561,7 @@ void pevent_free(struct pevent *pevent)
 	}
 
 	if (pevent->func_map) {
-		for (i = 0; i < pevent->func_count; i++) {
+		for (i = 0; i < (int)pevent->func_count; i++) {
 			free(pevent->func_map[i].func);
 			free(pevent->func_map[i].mod);
 		}
@@ -5583,7 +5583,7 @@ void pevent_free(struct pevent *pevent)
 	}
 
 	if (pevent->printk_map) {
-		for (i = 0; i < pevent->printk_count; i++)
+		for (i = 0; i < (int)pevent->printk_count; i++)
 			free(pevent->printk_map[i].printk);
 		free(pevent->printk_map);
 	}