wifi: ath5k: fix an off by one check in ath5k_eeprom_read_freq_list()

This loop checks that i < max at the start of loop but then it does
i++ which could put it past the end of the array.  It's harmless to
check again and prevent a potential out of bounds.

Fixes: 1048643e

 ("ath5k: Clean up eeprom parsing and add missing calibration data")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/Y+D9hPQrHfWBJhXz@kili