ALSA: sound/pci: use memdup_user()

Remove open-coded memdup_user().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/emu10k1/emufx.c b/sound/pci/emu10k1/emufx.c
index 191e1cd..4b302d8 100644
--- a/sound/pci/emu10k1/emufx.c
+++ b/sound/pci/emu10k1/emufx.c
@@ -2493,24 +2493,17 @@
 	case SNDRV_EMU10K1_IOCTL_CODE_POKE:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
-		icode = kmalloc(sizeof(*icode), GFP_KERNEL);
-		if (icode == NULL)
-			return -ENOMEM;
-		if (copy_from_user(icode, argp, sizeof(*icode))) {
-			kfree(icode);
-			return -EFAULT;
-		}
+
+		icode = memdup_user(argp, sizeof(*icode));
+		if (IS_ERR(icode))
+			return PTR_ERR(icode);
 		res = snd_emu10k1_icode_poke(emu, icode);
 		kfree(icode);
 		return res;
 	case SNDRV_EMU10K1_IOCTL_CODE_PEEK:
-		icode = kmalloc(sizeof(*icode), GFP_KERNEL);
-		if (icode == NULL)
-			return -ENOMEM;
-		if (copy_from_user(icode, argp, sizeof(*icode))) {
-			kfree(icode);
-			return -EFAULT;
-		}
+		icode = memdup_user(argp, sizeof(*icode));
+		if (IS_ERR(icode))
+			return PTR_ERR(icode);
 		res = snd_emu10k1_icode_peek(emu, icode);
 		if (res == 0 && copy_to_user(argp, icode, sizeof(*icode))) {
 			kfree(icode);
@@ -2519,24 +2512,16 @@
 		kfree(icode);
 		return res;
 	case SNDRV_EMU10K1_IOCTL_PCM_POKE:
-		ipcm = kmalloc(sizeof(*ipcm), GFP_KERNEL);
-		if (ipcm == NULL)
-			return -ENOMEM;
-		if (copy_from_user(ipcm, argp, sizeof(*ipcm))) {
-			kfree(ipcm);
-			return -EFAULT;
-		}
+		ipcm = memdup_user(argp, sizeof(*ipcm));
+		if (IS_ERR(ipcm))
+			return PTR_ERR(ipcm);
 		res = snd_emu10k1_ipcm_poke(emu, ipcm);
 		kfree(ipcm);
 		return res;
 	case SNDRV_EMU10K1_IOCTL_PCM_PEEK:
-		ipcm = kzalloc(sizeof(*ipcm), GFP_KERNEL);
-		if (ipcm == NULL)
-			return -ENOMEM;
-		if (copy_from_user(ipcm, argp, sizeof(*ipcm))) {
-			kfree(ipcm);
-			return -EFAULT;
-		}
+		ipcm = memdup_user(argp, sizeof(*ipcm));
+		if (IS_ERR(ipcm))
+			return PTR_ERR(ipcm);
 		res = snd_emu10k1_ipcm_peek(emu, ipcm);
 		if (res == 0 && copy_to_user(argp, ipcm, sizeof(*ipcm))) {
 			kfree(ipcm);