hooks/generate-gitrevs: simplify and just use "sourcepkg:gitshortrev".

Previous way was way too slow and somewhat redundant. Just with the
latest git short rev is enough to know at what point a pkg was built.

common/hooks/post-install/05-generate-gitrevs.sh

@@ -3,7 +3,7 @@
 
 hook() {
 	local GITREVS_FILE=${wrksrc}/.xbps_${sourcepkg}_git_revs
-	local _revs= _out= f= _filerev= _files=
+	local rev
 
 	# If XBPS_USE_GIT_REVS is disabled in conf file don't continue.
 	if [ -z $XBPS_USE_GIT_REVS ]; then
@@ -13,27 +13,9 @@ hook() {
 	if [ -s ${GITREVS_FILE} ]; then
 		return
 	fi
-	# Get the git revisions from this source pkg.
-	cd ${XBPS_SRCPKGDIR}
-	_files=$(git ls-files ${sourcepkg})
-	[ -z "${_files}" ] && return
 
-	for f in ${_files}; do
-		_filerev=$(git rev-list --abbrev-commit HEAD $f | head -n1)
-		[ -z "${_filerev}" ] && continue
-		_out="${f} ${_filerev}"
-		if [ -z "${_revs}" ]; then
-			_revs="${_out}"
-		else
-			_revs="${_revs} ${_out}"
-		fi
-	done
-
-	set -- ${_revs}
-	while [ $# -gt 0 ]; do
-		local _file=$1; local _rev=$2
-		echo "${_file}: ${_rev}"
-		echo "${_file}: ${_rev}" >> ${GITREVS_FILE}
-		shift 2
-	done
+	cd $XBPS_SRCPKGDIR
+	rev="$(git rev-parse --short HEAD)"
+	echo "${sourcepkg}:${rev}"
+	echo "${sourcepkg}:${rev}" > $GITREVS_FILE
 }