[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>

sound/usb/usbaudio.c

@@ -859,10 +859,8 @@ static void release_urb_ctx(snd_urb_ctx_t *u)
 		usb_free_urb(u->urb);
 		u->urb = NULL;
 	}
-	if (u->buf) {
-		kfree(u->buf);
-		u->buf = NULL;
-	}
+	kfree(u->buf);
+	u->buf = NULL;
 }
 
 /*
@@ -880,10 +878,8 @@ static void release_substream_urbs(snd_usb_substream_t *subs, int force)
 		release_urb_ctx(&subs->dataurb[i]);
 	for (i = 0; i < SYNC_URBS; i++)
 		release_urb_ctx(&subs->syncurb[i]);
-	if (subs->tmpbuf) {
-		kfree(subs->tmpbuf);
-		subs->tmpbuf = NULL;
-	}
+	kfree(subs->tmpbuf);
+	subs->tmpbuf = NULL;
 	subs->nurbs = 0;
 }
 

sound/usb/usbmixer.c

@@ -623,10 +623,8 @@ static struct usb_feature_control_info audio_feature_info[] = {
 /* private_free callback */
 static void usb_mixer_elem_free(snd_kcontrol_t *kctl)
 {
-	if (kctl->private_data) {
-		kfree(kctl->private_data);
-		kctl->private_data = NULL;
-	}
+	kfree(kctl->private_data);
+	kctl->private_data = NULL;
 }
 
 

sound/usb/usx2y/usbusx2yaudio.c

@@ -401,10 +401,8 @@ static void usX2Y_urbs_release(snd_usX2Y_substream_t *subs)
 	for (i = 0; i < NRURBS; i++)
 		usX2Y_urb_release(subs->urb + i, subs != subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK]);
 
-	if (subs->tmpbuf) {
-		kfree(subs->tmpbuf);
-		subs->tmpbuf = NULL;
-	}
+	kfree(subs->tmpbuf);
+	subs->tmpbuf = NULL;
 }
 /*
  * initialize a substream's urbs