[ALSA] Remove redundant NULL checks before kfree

Timer Midlevel,ALSA sequencer,ALSA<-OSS sequencer,Digigram VX core
I2C tea6330t,GUS Library,VIA82xx driver,VIA82xx-modem driver
CA0106 driver,CS46xx driver,EMU10K1/EMU10K2 driver,YMFPCI driver
Digigram VX Pocket driver,Common EMU synth,USB generic driver,USB USX2Y
Checking a pointer for NULL before calling kfree() on it is redundant,
kfree() deals with NULL pointers just fine.
This patch removes such checks from sound/

This patch also makes another, but closely related, change.
It avoids casting pointers about to be kfree()'ed.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/ca0106/ca0106_main.c b/sound/pci/ca0106/ca0106_main.c
index 85caf1b..0ec0c3e 100644
--- a/sound/pci/ca0106/ca0106_main.c
+++ b/sound/pci/ca0106/ca0106_main.c
@@ -332,11 +332,7 @@
 
 static void snd_ca0106_pcm_free_substream(snd_pcm_runtime_t *runtime)
 {
-	ca0106_pcm_t *epcm = runtime->private_data;
-  
-	if (epcm) {
-		kfree(epcm);
-	}
+	kfree(runtime->private_data);
 }
 
 /* open_playback callback */