mtd: rawnand: intel: use 'time_left' variable with wait_for_completion_timeout()

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Fix to the proper variable type 'unsigned long' while here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240604212919.5038-6-wsa+renesas@sang-engineering.com

drivers/mtd/nand/raw/intel-nand-controller.c

@@ -295,7 +295,7 @@ static int ebu_dma_start(struct ebu_nand_controller *ebu_host, u32 dir,
 	unsigned long flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
 	dma_addr_t buf_dma;
 	int ret;
-	u32 timeout;
+	unsigned long time_left;
 
 	if (dir == DMA_DEV_TO_MEM) {
 		chan = ebu_host->dma_rx;
@@ -335,8 +335,8 @@ static int ebu_dma_start(struct ebu_nand_controller *ebu_host, u32 dir,
 	dma_async_issue_pending(chan);
 
 	/* Wait DMA to finish the data transfer.*/
-	timeout = wait_for_completion_timeout(dma_completion, msecs_to_jiffies(1000));
-	if (!timeout) {
+	time_left = wait_for_completion_timeout(dma_completion, msecs_to_jiffies(1000));
+	if (!time_left) {
 		dev_err(ebu_host->dev, "I/O Error in DMA RX (status %d)\n",
 			dmaengine_tx_status(chan, cookie, NULL));
 		dmaengine_terminate_sync(chan);