ath9k: Fix modal EEPROM dump

we provide excess buffer size for 'simple_read_from_buffer'
for modal EEPROM dump. This results in trailing NULL bytes
at the end of EEPROM dump, fix this.

Cc: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Reported-by: Holger Schurig <holgerschurig@googlemail.com>
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Tested-by: Holger Schurig <holgerschurig@gogglemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ar9003_eeprom.c

@@ -3412,11 +3412,11 @@ static u32 ath9k_hw_ar9003_dump_eeprom(struct ath_hw *ah, bool dump_base_hdr,
 	if (!dump_base_hdr) {
 		len += snprintf(buf + len, size - len,
 				"%20s :\n", "2GHz modal Header");
-		len += ar9003_dump_modal_eeprom(buf, len, size,
+		len = ar9003_dump_modal_eeprom(buf, len, size,
 						&eep->modalHeader2G);
 		len += snprintf(buf + len, size - len,
 				"%20s :\n", "5GHz modal Header");
-		len += ar9003_dump_modal_eeprom(buf, len, size,
+		len = ar9003_dump_modal_eeprom(buf, len, size,
 						&eep->modalHeader5G);
 		goto out;
 	}

drivers/net/wireless/ath/ath9k/eeprom_4k.c

@@ -135,7 +135,7 @@ static u32 ath9k_hw_4k_dump_eeprom(struct ath_hw *ah, bool dump_base_hdr,
 	if (!dump_base_hdr) {
 		len += snprintf(buf + len, size - len,
 				"%20s :\n", "2GHz modal Header");
-		len += ath9k_dump_4k_modal_eeprom(buf, len, size,
+		len = ath9k_dump_4k_modal_eeprom(buf, len, size,
 						  &eep->modalHeader);
 		goto out;
 	}

drivers/net/wireless/ath/ath9k/eeprom_9287.c

@@ -132,7 +132,7 @@ static u32 ath9k_hw_ar9287_dump_eeprom(struct ath_hw *ah, bool dump_base_hdr,
 	if (!dump_base_hdr) {
 		len += snprintf(buf + len, size - len,
 				"%20s :\n", "2GHz modal Header");
-		len += ar9287_dump_modal_eeprom(buf, len, size,
+		len = ar9287_dump_modal_eeprom(buf, len, size,
 						&eep->modalHeader);
 		goto out;
 	}

drivers/net/wireless/ath/ath9k/eeprom_def.c

@@ -211,11 +211,11 @@ static u32 ath9k_hw_def_dump_eeprom(struct ath_hw *ah, bool dump_base_hdr,
 	if (!dump_base_hdr) {
 		len += snprintf(buf + len, size - len,
 				"%20s :\n", "2GHz modal Header");
-		len += ath9k_def_dump_modal_eeprom(buf, len, size,
+		len = ath9k_def_dump_modal_eeprom(buf, len, size,
 						   &eep->modalHeader[0]);
 		len += snprintf(buf + len, size - len,
 				"%20s :\n", "5GHz modal Header");
-		len += ath9k_def_dump_modal_eeprom(buf, len, size,
+		len = ath9k_def_dump_modal_eeprom(buf, len, size,
 						   &eep->modalHeader[1]);
 		goto out;
 	}