aws: Fix typo in Handlers doc comments

[rittneje]

Fixed a few doc comment typos I found.

[rittneje]

My best guess is that the test failure is due to an existing race condition.

aws-sdk-go/aws/request/http_request_retry_test.go

Lines 31 to 34 in 0a6eb5a

	err := r.Send()
	if !strings.Contains(err.Error(), "canceled") {
	t.Errorf("expect canceled in error, %v", err)
	}

If r.Send() manages to succeed despite being canceled, it will return nil, resulting in a panic when the test calls err.Error().

[jasdel]

--- FAIL: TestRequestCancelRetry (0.00s)

panic: runtime error: invalid memory address or nil pointer dereference [recovered]

	panic: runtime error: invalid memory address or nil pointer dereference

[signal 0xb code=0x1 addr=0x20 pc=0x4d698c]

goroutine 841 [running]:

testing.tRunner.func1(0xc820f610e0)

	/tmp/workdir/go/src/testing/testing.go:450 +0x1f5

github.com/aws/aws-sdk-go/aws/request_test.TestRequestCancelRetry(0xc820f610e0)

	/home/travis/gopath/src/github.com/aws/aws-sdk-go/aws/request/http_request_retry_test.go:32 +0x8ac

testing.tRunner(0xc820f610e0, 0x1397350)

	/tmp/workdir/go/src/testing/testing.go:456 +0xdd

created by testing.RunTests

	/tmp/workdir/go/src/testing/testing.go:561 +0xaa4

goroutine 1 [chan receive]:

testing.RunTests(0x105b930, 0x1397080, 0x50, 0x50, 0xc8201ae601)

	/tmp/workdir/go/src/testing/testing.go:562 +0xafa

testing.(*M).Run(0xc8232fff00, 0x1)

	/tmp/workdir/go/src/testing/testing.go:494 +0xe5

main.main()

	github.com/aws/aws-sdk-go/aws/request/_test/_testmain.go:234 +0x210

goroutine 17 [syscall, locked to thread]:

runtime.goexit()

	/tmp/workdir/go/src/runtime/asm_amd64.s:1721 +0x1

[jasdel]

Also looks like TestEnforceShouldRetryCheck test case isn't cleanup up its server either.

[jasdel]

Create #2840 for the test failure.