staging: serqt_usb2: Remove NULL check before kfree

This patch was generated by the following semantic patch:
// <smpl>
@@ expression E; @@
- if (E != NULL) { kfree(E); }
+ kfree(E);

@@ expression E; @@
- if (E != NULL) { kfree(E); E = NULL; }
+ kfree(E);
+ E = NULL;
// </smpl>

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/serqt_usb2/serqt_usb2.c

@@ -1098,8 +1098,7 @@ static void qt_close(struct usb_serial_port *port)
 
 	if (qt_port->write_urb) {
 		/* if this urb had a transfer buffer already (old tx) free it */
-		if (qt_port->write_urb->transfer_buffer != NULL)
-			kfree(qt_port->write_urb->transfer_buffer);
+		kfree(qt_port->write_urb->transfer_buffer);
 		usb_free_urb(qt_port->write_urb);
 	}