Revert "Dealing with trailing whitespaces"

The validation script from #10681 is too pedantic, and does not handle
well situations like:

```
cat <<EOF   # or <<-EOF
	Whether the leading whitespace is stripped out or not by bash
	it should still be considered as valid.
EOF
```

This reverts commit 4e65c1c319.

Signed-off-by: Tibor Vass <tibor@docker.com>

Makefile

@@ -77,7 +77,7 @@ test-docker-py: build
 	$(DOCKER_RUN_DOCKER) hack/make.sh binary test-docker-py
 
 validate: build
-	$(DOCKER_RUN_DOCKER) hack/make.sh validate-gofmt validate-dco validate-toml validate-spaces
+	$(DOCKER_RUN_DOCKER) hack/make.sh validate-gofmt validate-dco validate-toml
 
 shell: build
 	$(DOCKER_RUN_DOCKER) bash

hack/make.sh

@@ -45,7 +45,6 @@ DEFAULT_BUNDLES=(
 	validate-dco
 	validate-gofmt
 	validate-toml
-	validate-spaces
 
 	binary
 

hack/make/validate-spaces

@@ -1,33 +0,0 @@
-#!/bin/bash
-
-source "$(dirname "$BASH_SOURCE")/.validate"
-
-#Ignoring files from vendor/, builder/parser/testfiles*, docs/theme/mkdocs/tipuesearch*, ending with .md and .go
-ignoreFiles='^builder/parser/testfiles*|^docs/theme/mkdocs/tipuesearch*|^vendor/|\.md$|\.go$'
-
-IFS=$'\n'
-files=( $(validate_diff --diff-filter=ACMR --name-only | grep -v "$ignoreFiles" || true) )
-unset IFS
-
-badFiles=()
-for f in "${files[@]}"; do
-    if [ "$(git show "$VALIDATE_HEAD:$f" | grep '[[:space:]]$')" ]; then
-        badFiles+=( "$f" )
-    fi
-done
-
-if [ ${#badFiles[@]} -eq 0 ]; then
-	echo 'Congratulations!  All text files are properly formatted.'
-else
-	{
-		echo "These files have trailing whitespaces:"
-		for f in "${badFiles[@]}"; do
-			echo " - $f"
-		done
-		echo
-		echo 'Please reformat the above files using, for example:'
-		echo '"ex -sc "'"%s/[[:space:]]*$//g|x"'" file" and commit the result.'
-		echo
-	} >&2
-	false
-fi