[AArch64] Remove BFD overflow check restrictions

[Nicholas Clifton]

Hi Jiong,

> OK for trunk and 2.25 backport?
>
> Thanks.
>
> 2015-05-12  Jiong Wang  <jiong.wang@arm.com>
>
> bfd/
>    * elfnn-aarch64.c (elfNN_aarch64_relocate_section): Remove overflow check restrictions.

OK for the mainline.

Cheers
   Nick