perf tools: Move dereference after NULL test

In each case, if the NULL test on thread is needed, then the
dereference should be after the NULL test.

A simplified version of the semantic match that detects this
problem is as follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
  ... when != \(x = E\|&x\)
* x == NULL
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
LKML-Reference: <Pine.LNX.4.64.0910170842500.9213@ask.diku.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index c9c6856..57ad3f4 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1667,14 +1667,14 @@
 		(void *)(long)ip,
 		(long long)period);
 
-	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
-
 	if (thread == NULL) {
 		eprintf("problem processing %d event, skipping it.\n",
 			event->header.type);
 		return -1;
 	}
 
+	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+
 	if (profile_cpu != -1 && profile_cpu != (int) cpu)
 		return 0;