Input: xilinx_ps2 - use guard notation when acquiring spinlock

Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Torokhov <[email protected]>

Author: dtor

drivers/input/serio/xilinx_ps2.c

@@ -155,22 +155,17 @@ static irqreturn_t xps2_interrupt(int irq, void *dev_id)
 static int sxps2_write(struct serio *pserio, unsigned char c)
 {
 	struct xps2data *drvdata = pserio->port_data;
-	unsigned long flags;
 	u32 sr;
-	int status = -1;
 
-	spin_lock_irqsave(&drvdata->lock, flags);
+	guard(spinlock_irqsave)(&drvdata->lock);
 
 	/* If the PS/2 transmitter is empty send a byte of data */
 	sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
-	if (!(sr & XPS2_STATUS_TX_FULL)) {
-		out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
-		status = 0;
-	}
+	if (sr & XPS2_STATUS_TX_FULL)
+		return -EAGAIN;
 
-	spin_unlock_irqrestore(&drvdata->lock, flags);
-
-	return status;
+	out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
+	return 0;
 }
 
 /**