Staging: rtl8188eu: remove dead code

The condition pxmitpriv->hwxmit_entry == 5 is always false because
HWXMIT_ENTRY is always 4.

Signed-off-by: Matteo Semenzato <mattew8898@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>