iwlegacy: Return directly if allocation fails in il_eeprom_init()

Also remove an unused label.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
[Rewrote commit message]
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>