ath5k: fix memory leak on buf on failed eeprom read

The AR5K_EEPROM_READ macro returns with -EIO if a read error
occurs causing a memory leak on the allocated buffer buf. Fix
this by explicitly calling ath5k_hw_nvram_read and exiting on
the via the freebuf label that performs the necessary free'ing
of buf when a read error occurs.

Detected by CoverityScan, CID#1248782 ("Resource Leak")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

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

@@ -938,7 +938,10 @@ static int open_file_eeprom(struct inode *inode, struct file *file)
 	}
 
 	for (i = 0; i < eesize; ++i) {
-		AR5K_EEPROM_READ(i, val);
+		if (!ath5k_hw_nvram_read(ah, i, &val)) {
+			ret = -EIO;
+			goto freebuf;
+		}
 		buf[i] = val;
 	}