adm8211: fix memory leak

We must free priv->eeprom allocated in adm8211_read_eeprom().

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>