[patch] add missing ] to as.texinfo

[Nick Clifton]

Hi Mike,

> trivial patch i noticed while reading the docs
> http://sourceware.org/binutils/docs-2.16/as/Section.html#Section
> 
> For ELF targets, the .section directive is used like this:
> 
>      .section name [, "flags"[, @type[,flag_specific_arguments]]
> 
> needs three ]

Thanks - patch applied.

Cheers
   Nick