i3c: master: renesas: Fix memory leak in renesas_i3c_i3c_xfers()

The xfer structure allocated by renesas_i3c_alloc_xfer() was never freed
in the renesas_i3c_i3c_xfers() function. Use the __free(kfree) cleanup
attribute to automatically free the memory when the variable goes out of
scope.

Fixes: d028219 ("i3c: master: Add basic driver for the Renesas I3C controller")
Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Link: https://patch.msgid.link/20260406-renesas-v3-1-4b724d7708f4@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: outman119

drivers/i3c/master/renesas-i3c.c

@@ -8,6 +8,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/err.h>
@@ -817,13 +818,12 @@ static int renesas_i3c_i3c_xfers(struct i3c_dev_desc *dev, struct i3c_xfer *i3c_
 	struct i3c_master_controller *m = i3c_dev_get_master(dev);
 	struct renesas_i3c *i3c = to_renesas_i3c(m);
 	struct renesas_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
-	struct renesas_i3c_xfer *xfer;
 	int i;
 
 	/* Enable I3C bus. */
 	renesas_i3c_bus_enable(m, true);
 
-	xfer = renesas_i3c_alloc_xfer(i3c, 1);
+	struct renesas_i3c_xfer *xfer __free(kfree) = renesas_i3c_alloc_xfer(i3c, 1);
 	if (!xfer)
 		return -ENOMEM;