Fix gus_pcm dereference before NULL

[Eugene Teo]

substream is dereferenced before checking for NULL.

Coverity bug #861

Signed-off-by: Eugene Teo <eugene.teo@xxxxxxxxxxxxx>

--- linux-2.6/sound/isa/gus/gus_pcm.c~	2006-03-15 10:05:45.000000000 +0800
+++ linux-2.6/sound/isa/gus/gus_pcm.c	2006-03-16 09:51:43.000000000 +0800
@@ -103,8 +103,8 @@
 
 static void snd_gf1_pcm_trigger_up(struct snd_pcm_substream *substream)
 {
-	struct snd_pcm_runtime *runtime = substream->runtime;
-	struct gus_pcm_private *pcmp = runtime->private_data;
+	struct snd_pcm_runtime *runtime;
+	struct gus_pcm_private *pcmp;
 	struct snd_gus_card * gus = pcmp->gus;
 	unsigned long flags;
 	unsigned char voice_ctrl, ramp_ctrl;
@@ -114,8 +114,10 @@
 	unsigned char pan;
 	unsigned int voice;
 
-	if (substream == NULL)
+	if (substream == NULL || substream->runtime == NULL)
 		return;
+	runtime = substream->runtime;
+	pcmp = runtime->private_data;
 	spin_lock_irqsave(&pcmp->lock, flags);
 	if (pcmp->flags & SNDRV_GF1_PCM_PFLG_ACTIVE) {
 		spin_unlock_irqrestore(&pcmp->lock, flags);

-- 
1024D/A6D12F80 print D51D 2633 8DAC 04DB 7265  9BB8 5883 6DAA A6D1 2F80
main(i) { putchar(182623909 >> (i-1) * 5&31|!!(i<7)<<6) && main(++i); }

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