[rfa] Fix signed modulo arrith in elf.c

[Andrew Cagney]

> Hi Andrew,
> 
> 
>> 	* elf.c: Update copyright.
>> 	(vma_page_aligned_bias): New function.
>> 	(assign_file_positions_except_relocs)
>> 	(assign_file_positions_for_segments): Replace broken modulo
>> 	arithmetic with call to vma_page_aligned_bias.
> 
> 
> Approved - please apply.
> 
> (Note - we normally do not mention updates to the Copyright notice.
> At least not when just adding a new year).

Committed (minus "Update copyright").

Andrew