zsh:diffcmds(): Add a layer of quotation

Add a layer of quotation as eval removes one. For example using
parameters in single quotes would still be expanded.

.config/zsh/zshrc.d/40-functions.zsh

@@ -670,7 +670,7 @@ diffcmds() {
 
 	cmdline=("$cmd")
 	for arg in "${@:$((i+1))}"; do
-		cmdline+=("=(" "${(@)${@:1:$((i-1))}//\%\%/$arg}" ")")
+		cmdline+=("=(" "${(q@)${@:1:$((i-1))}//\%\%/$arg}" ")")
 	done
 	eval "$cmdline[@]"
 }