mwl8k: undo transmit queue 0/1 swapping in mwl8k_cmd_set_edca_params()

The comment and code in mwl8k_cmd_set_edca_params() suggest that the
mapping between SET_EDCA_PARAMS queue numbers and transmit rings isn't
actually 1:1, while tests show that the mapping is in fact 1:1.  So,
get rid of the transmit queue 0/1 swapping.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>