tools: xenalyze: kill spurious sched_switch output in non dump mode.

In fact, 52cf096df7 ("xenalyze: handle scheduling event"),
when dealing with TRC_SCHED_SWITCH, forgot to check whether
we actually are in dump mode, causing the printf() in
dump_sched_switch() to always produce its output, which
is not what we want.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>

tools/xentrace/xenalyze.c

@@ -7629,7 +7629,8 @@ void sched_process(struct pcpu_info *p)
             }
             break;
         case TRC_SCHED_SWITCH:
-            dump_sched_switch(ri);
+            if(opt.dump_all)
+                dump_sched_switch(ri);
             break;
         case TRC_SCHED_SWITCH_INFPREV:
             if(opt.dump_all) {