uboot-imx

MLK-12214 NAND:apbh_dma: Fix logically dead code issue

The list_first_entry always assumes the list is not empty, it won't return NULL pointer when
the list is empty. So the "if (pdesc == NULL)" becomes a dead code. Fix the issue by calling
the list_empty before the list_first_entry.

(Coverity CID 29934)

Signed-off-by: Ye.Li <ye.li@nxp.com>
(cherry picked from commit ff3923f294cc2e15f436d7520b4042736b1b48a6)
(cherry picked from commit 64c6a7b5d621080b8bd948c061a4f223a8c2d886)
(cherry picked from commit b9846931a2196fa2bf29a9cb0304d11e96c2c40a)