mkpkg: Fix quoting of array variables

Uniformly use the expension flag instead of the modifier.

Use single quotes instead of backslashes for the outer quoting to reduce
the amount of quoting needed.

roles/archbuild/files/mkpkg

@@ -154,14 +154,14 @@ repoadd() {
   if [[ -n $repohost ]]; then
     ssh -q $repohost mkdir -p $repodir/$1
     scp -q $files $repohost:$repodir/$1/
-    ssh -q $repohost zsh -c ${(q):-":
+    ssh -q $repohost zsh -c ${(qq):-":
       setopt extendedglob nomatch
-      repodir=${repodir:q}
-      repodb=${repodb:q}
-      pkgname=(${pkgname:q})
-      files=(${files:q})
+      repodir=${(q)repodir}
+      repodb=${(q)repodb}
+      pkgname=(${"${(@q)pkgname}"})
+      files=(${"${(@q)files}"})
       $(declare -f repoadd_remote)
-      repoadd_remote ${1:q}
+      repoadd_remote ${(q)1}
     "}
   else
     mkdir -p $repodir/$1