Revert "usb: gadget: u_serial: Disable ep before setting port to null to fix the crash caused by port being null"

This reverts commit 13014969cbf07f18d62ceea40bd8ca8ec9d36cec.

It is reported to cause crashes on Tegra systems, so revert it for now.

Link: https://lore.kernel.org/r/[e-mail]
Reported-by: Jon Hunter <[e-mail]>
Cc: stable <[e-mail]>
Cc: Lianqin Hu <[e-mail]>
Link: https://lore.kernel.org/r/2025011711-yippee-fever-a737@gregkh
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/function/u_serial.c

···
 	/* REVISIT as above: how best to track this? */
 	port->port_line_coding = gser->port_line_coding;
 
-	/* disable endpoints, aborting down any active I/O */
-	usb_ep_disable(gser->out);
-	usb_ep_disable(gser->in);
-
 	port->port_usb = NULL;
 	gser->ioport = NULL;
 	if (port->port.count > 0) {
···
 	port->suspended = false;
 	spin_unlock(&port->port_lock);
 	spin_unlock_irqrestore(&serial_port_lock, flags);
+
+	/* disable endpoints, aborting down any active I/O */
+	usb_ep_disable(gser->out);
+	usb_ep_disable(gser->in);
 
 	/* finally, free any unused/unusable I/O buffers */
 	spin_lock_irqsave(&port->port_lock, flags);