ath5k: fix uninitialized var warning for txf2txs

CC [M]  drivers/net/wireless/ath/ath5k/reset.o
drivers/net/wireless/ath/ath5k/reset.c: In function ‘ath5k_hw_init_core_clock’:
drivers/net/wireless/ath/ath5k/reset.c💯51: warning: ‘txf2txs’ may be used uninitialized in this function

Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -158,6 +158,11 @@ static void ath5k_hw_init_core_clock(struct ath5k_hw *ah)
 	txlat = AR5K_REG_MS(usec_reg, AR5K_USEC_TX_LATENCY_5211);
 	rxlat = AR5K_REG_MS(usec_reg, AR5K_USEC_RX_LATENCY_5211);
 
+	/*
+	 * Set default Tx frame to Tx data start delay
+	 */
+	txf2txs = AR5K_INIT_TXF2TXD_START_DEFAULT;
+
 	/*
 	 * 5210 initvals don't include usec settings
 	 * so we need to use magic values here for