ath5k: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1].

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200727194930.GA1491@embeddedor

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

@@ -1172,13 +1172,13 @@ ath5k_cal_data_offset_2413(struct ath5k_eeprom_info *ee, int mode)
 			offset += ath5k_pdgains_size_2413(ee,
 					AR5K_EEPROM_MODE_11B) +
 					AR5K_EEPROM_N_2GHZ_CHAN_2413 / 2;
-		/* fall through */
+		fallthrough;
 	case AR5K_EEPROM_MODE_11B:
 		if (AR5K_EEPROM_HDR_11A(ee->ee_header))
 			offset += ath5k_pdgains_size_2413(ee,
 					AR5K_EEPROM_MODE_11A) +
 					AR5K_EEPROM_N_5GHZ_CHAN / 2;
-		/* fall through */
+		fallthrough;
 	case AR5K_EEPROM_MODE_11A:
 		break;
 	default:

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

@@ -670,7 +670,7 @@ ath5k_hw_init_beacon_timers(struct ath5k_hw *ah, u32 next_beacon, u32 interval)
 		break;
 	case NL80211_IFTYPE_ADHOC:
 		AR5K_REG_ENABLE_BITS(ah, AR5K_TXCFG, AR5K_TXCFG_ADHOC_BCN_ATIM);
-		/* fall through */
+		fallthrough;
 	default:
 		/* On non-STA modes timer1 is used as next DMA
 		 * beacon alert (DBA) timer and timer2 as next
@@ -913,7 +913,7 @@ ath5k_hw_set_opmode(struct ath5k_hw *ah, enum nl80211_iftype op_mode)
 		pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
 			| (ah->ah_version == AR5K_AR5210 ?
 				AR5K_STA_ID1_PWR_SV : 0);
-		/* fall through */
+		fallthrough;
 	case NL80211_IFTYPE_MONITOR:
 		pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
 			| (ah->ah_version == AR5K_AR5210 ?

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

@@ -3229,10 +3229,10 @@ ath5k_write_pwr_to_pdadc_table(struct ath5k_hw *ah, u8 ee_mode)
 	switch (pdcurves) {
 	case 3:
 		reg |= AR5K_REG_SM(pdg_to_idx[2], AR5K_PHY_TPC_RG1_PDGAIN_3);
-		/* Fall through */
+		fallthrough;
 	case 2:
 		reg |= AR5K_REG_SM(pdg_to_idx[1], AR5K_PHY_TPC_RG1_PDGAIN_2);
-		/* Fall through */
+		fallthrough;
 	case 1:
 		reg |= AR5K_REG_SM(pdg_to_idx[0], AR5K_PHY_TPC_RG1_PDGAIN_1);
 		break;
@@ -3353,7 +3353,7 @@ ath5k_setup_channel_powertable(struct ath5k_hw *ah,
 					table_min[pdg] = table_max[pdg] - 126;
 			}
 
-			/* Fall through */
+			fallthrough;
 		case AR5K_PWRTABLE_PWR_TO_PCDAC:
 		case AR5K_PWRTABLE_PWR_TO_PDADC:
 

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

@@ -522,7 +522,7 @@ ath5k_hw_set_power_mode(struct ath5k_hw *ah, enum ath5k_power_mode mode,
 	switch (mode) {
 	case AR5K_PM_AUTO:
 		staid &= ~AR5K_STA_ID1_DEFAULT_ANTENNA;
-		/* fallthrough */
+		fallthrough;
 	case AR5K_PM_NETWORK_SLEEP:
 		if (set_chip)
 			ath5k_hw_reg_write(ah,