*.sh: Fix some shellcheck issues

.config/git/zsh-autoload.sh

@@ -6,20 +6,22 @@
 # correct directory.
 
 if [ $# -eq 0 ]; then
-	printf >&2 "Usage: $(basename "$0") <function>\n"
+	printf >&2 "Usage: %s <function>\n" "$(basename "$0")"
 	exit 1
 fi
+name="$1"
+shift
 
 BASE="${XDG_CONFIG_HOME:-$HOME/.config}/zsh/autoload/git"
 
 # In git aliases, shell commands are executed from the top-level directory of
 # the repo. GIT_PREFIX contains the original directory relative to the
 # top-level.
-[ -z "$GIT_PREFIX" ] || cd "$GIT_PREFIX"
+[ -z "$GIT_PREFIX" ] || cd "$GIT_PREFIX" || exit
 
 # no need for error handling, the message from sh is descriptive enough
-if [ "${1#git-}" != "$1" ] || [ -e "$BASE/$1" ]; then
-	exec "$BASE/$@"
+if [ "${name#git-}" != "$name" ] || [ -e "$BASE/$name" ]; then
+	exec "$BASE/$name" "$@"
 else
-	exec "$BASE/git-$@"
+	exec "$BASE/git-$name" "$@"
 fi