net: Fix memcpy_toiovecend() to use the right offset

Increment the iovec base by the offset passed in for the initial
copy_to_user() in memcpy_to_iovecend().
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/iovec.c

@@ -112,9 +112,9 @@ int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata,
 			continue;
 		}
 		copy = min_t(unsigned int, iov->iov_len - offset, len);
-		offset = 0;
-		if (copy_to_user(iov->iov_base, kdata, copy))
+		if (copy_to_user(iov->iov_base + offset, kdata, copy))
 			return -EFAULT;
+		offset = 0;
 		kdata += copy;
 		len -= copy;
 	}