dmaengine: stm32-mdma: fix chan initialization in stm32_mdma_irq_handler()

The parameter to pass back to the handler function when irq has been
requested is a struct stm32_mdma_device pointer, not a struct
stm32_mdma_chan pointer.
Even if chan is reinit later in the function, remove this wrong
initialization.

Fixes: a4ffb13c ("dmaengine: Add STM32 MDMA driver")
Signed-off-by: NAmelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20220504155322.121431-3-amelie.delaunay@foss.st.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

drivers/dma/stm32-mdma.c

@@ -1318,7 +1318,7 @@ static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
 static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
 {
 	struct stm32_mdma_device *dmadev = devid;
-	struct stm32_mdma_chan *chan = devid;
+	struct stm32_mdma_chan *chan;
 	u32 reg, id, ccr, ien, status;
 
 	/* Find out which channel generates the interrupt */