[CI] Revert to previous logic for branch name and changes (#7343)

util/travis_utils.sh

@@ -10,8 +10,8 @@ TRAVIS_COMMIT_RANGE="${TRAVIS_COMMIT_RANGE:-HEAD~1..HEAD}"
 #TRAVIS_COMMIT_RANGE="c287f1bfc5c8...81f62atc4c1d"
 
 # Extra variables
-LOCAL_BRANCH=${TRAVIS_PULL_REQUEST_BRANCH:-${TRAVIS_BRANCH}}
-QMK_CHANGES=$(git diff --name-only HEAD ${TRAVIS_BRANCH})
+LOCAL_BRANCH=$(git rev-parse --abbrev-ref HEAD)
+QMK_CHANGES=$(git diff --name-only -n 1 ${TRAVIS_COMMIT_RANGE})
 
 # if docker is installed - patch calls to within the qmk docker image
 if command -v docker >/dev/null; then