scripts: Change here document delimiters

Fix the outstanding scripts using non standard shell here document delimiters.

This should have been caught by
https://github.com/kata-containers/tests/pull/3937, but there is a bug
in the checker which is fixed on
https://github.com/kata-containers/tests/pull/4569.

Fixes: #3864.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

tools/packaging/guest-image/build_image.sh

@@ -59,7 +59,7 @@ build_image() {
 
 usage() {
 	return_code=${1:-0}
-	cat <<EOT
+	cat <<EOF
 Create image and initrd in a tarball for kata containers.
 Use it to build an image to distribute kata.
 
@@ -70,7 +70,7 @@ Options:
  --imagetype=${image_type}
  --prefix=${prefix}
  --destdir=${destdir}
-EOT
+EOF
 
 	exit "${return_code}"
 }