FontList: skip Kindle blacklisted fonts (#11932)

Closes #11927.

frontend/fontlist.lua

@@ -142,12 +142,10 @@ function FontList:_readList(dir, mark)
         -- See if we're interested
         if file:sub(1, 1) == "." then return end
         local file_type = file:lower():match(".+%.([^.]+)") or ""
-        if not font_exts[file_type] then return end
+        if not font_exts[file_type] or isInFontsBlacklist(file) then return end
 
         -- Add it to the list
-        if not isInFontsBlacklist(file) then
-            table.insert(self.fontlist, path)
-        end
+        table.insert(self.fontlist, path)
 
         -- And into cached info table
         mark[path] = true