ath5k: Fix I/Q calibration

The sign of correction coefficients was lost in the calculations, which
caused high packetloss in 802.11a mode after the results were applied.
Fixed by removing unneccesary and broken AND with a bit mask.

Signed-off-by: Lukas Turek <8an@praha12.net>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/phy.c

@@ -1399,15 +1399,15 @@ static int ath5k_hw_rf511x_calibrate(struct ath5k_hw *ah,
 	if (i_coffd == 0 || q_coffd == 0)
 		goto done;
 
-	i_coff = ((-iq_corr) / i_coffd) & 0x3f;
+	i_coff = ((-iq_corr) / i_coffd);
 
 	/* Boundary check */
 	if (i_coff > 31)
 		i_coff = 31;
 	if (i_coff < -32)
 		i_coff = -32;
 
-	q_coff = (((s32)i_pwr / q_coffd) - 128) & 0x1f;
+	q_coff = (((s32)i_pwr / q_coffd) - 128);
 
 	/* Boundary check */
 	if (q_coff > 15)