staging: usbip: 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/usbip/stub_main.c

@@ -264,11 +264,9 @@ void stub_device_cleanup_urbs(struct stub_device *sdev)
 
 		kmem_cache_free(stub_priv_cache, priv);
 
-		if (urb->transfer_buffer != NULL)
-			kfree(urb->transfer_buffer);
+		kfree(urb->transfer_buffer);
 
-		if (urb->setup_packet != NULL)
-			kfree(urb->setup_packet);
+		kfree(urb->setup_packet);
 
 		usb_free_urb(urb);
 	}