uwb/whci: Delete an unnecessary check before the function call "umc_device_unregister"

The umc_device_unregister() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/uwb/whci.c

@@ -133,8 +133,7 @@ static void whci_del_cap(struct whci_card *card, int n)
 {
 	struct umc_dev *umc = card->devs[n];
 
-	if (umc != NULL)
-		umc_device_unregister(umc);
+	umc_device_unregister(umc);
 }
 
 static int whci_n_caps(struct pci_dev *pci)