mtd: rawnand: lpc32xx_slc: fail DMA transfer on completion timeout

In the Linux kernel, the following vulnerability has been resolved: mtd: rawnand: lpc32xx_slc: fail DMA transfer on completion timeout lpc32xx_xmit_dma() waits for the DMA completion callback but ignores wait_for_completion_timeout(). A timed out DMA transfer is therefore unmapped and reported as successful to the NAND read/write path. Return -ETIMEDOUT when the completion wait expires. Terminate the DMA channel before unmapping the scatterlist so the timed out transfer cannot continue to access the buffer after the error is returned.