fix: use exit instead of return

Signed-off-by: wxiwnd <wxiwnd@outlook.com>

Author: wxiwnd

scripts/bash_pinyin_completion

@@ -7,7 +7,7 @@
 # Detect bash-completion
 if ! declare -F _comp_compgen_filedir &>/dev/null; then
     echo "No function _comp_compgen_filedir found. Please install bash-completion first."
-    return
+    exit 1
 fi
 
 eval "function __bak_comp_compgen_filedir() { $(declare -f _comp_compgen_filedir | tail -n +2) }"