[PATCH] staging: r8188eu: Use memdup_user instead of kmalloc/copy_from_user

[Wan Jiabing]

Fix following coccicheck warning:
./drivers/staging/r8188eu/os_dep/ioctl_linux.c:1986:8-15: WARNING
opportunity for memdup_user.

Use memdup_user rather than duplicating its implementation, which
makes code simple and easy to understand.

Signed-off-by: Wan Jiabing <wanjiabing@xxxxxxxx>
---
 drivers/staging/r8188eu/os_dep/ioctl_linux.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
index 4f0ae821d193..301a29984fad 100644
--- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c
@@ -1983,14 +1983,9 @@ static int rtw_wx_read32(struct net_device *dev,
 	padapter = (struct adapter *)rtw_netdev_priv(dev);
 	p = &wrqu->data;
 	len = p->length;
-	ptmp = kmalloc(len, GFP_KERNEL);
-	if (!ptmp)
-		return -ENOMEM;
-
-	if (copy_from_user(ptmp, p->pointer, len)) {
-		kfree(ptmp);
-		return -EFAULT;
-	}
+	ptmp = memdup_user(p->pointer, len);
+	if (IS_ERR(ptmp))
+		return PTR_ERR(ptmp);
 
 	bytes = 0;
 	addr = 0;
-- 
2.20.1