eeprom: idt_89hpesx: Discard memory freeing allocated by devm_kmalloc

Indeed, the data structure is allocated by device resource manager,
so the driver doesn't need to free anything on remove() callback.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>