mtd: fsl-quadspi: cleanup wait_for_completion return handling

return type of wait_for_completion_timeout is unsigned long not int, this
patch uses the return value of wait_for_completion_timeout in the condition
directly rather than adding a additional appropriately typed variable.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Han Xu <han.xu@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/spi-nor/fsl-quadspi.c

@@ -460,8 +460,7 @@ fsl_qspi_runcmd(struct fsl_qspi *q, u8 cmd, unsigned int addr, int len)
 	writel((seqid << QUADSPI_IPCR_SEQID_SHIFT) | len, base + QUADSPI_IPCR);
 
 	/* Wait for the interrupt. */
-	err = wait_for_completion_timeout(&q->c, msecs_to_jiffies(1000));
-	if (!err) {
+	if (!wait_for_completion_timeout(&q->c, msecs_to_jiffies(1000))) {
 		dev_err(q->dev,
 			"cmd 0x%.2x timeout, addr@%.8x, FR:0x%.8x, SR:0x%.8x\n",
 			cmd, addr, readl(base + QUADSPI_FR),