* provider/aws: Add errcheck to Makefile, error on unchecked errors
* more exceptions
* updates for errcheck to pass
* reformat and spilt out the ignore statements
* narrow down ignores
* fix typo, only ignore Close and Write, instead of close or write
Previously the format string was using %#v, which prints the whole data structure given.
Instead we want to use %s to get the string representation of the error.
This fixes#6038.
This landed in aws-sdk-go yesterday, breaking the AWS provider in many places:
3c259c9586
Here, with much sedding, grepping, and manual massaging, we attempt to
catch Terraform up to the new `awserr.Error` interface world.
Clint