Don't warn repeatedly about an existing LLVM dir

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

build/llvm/LLVM.lua

@@ -187,9 +187,12 @@ function download_llvm()
   -- check if we already have the file downloaded
   if os.isfile(archive) then
     print("Archive " .. archive .. " already exists.")
+	return
   elseif os.isdir(pkg_name) then
     print("Directory " .. pkg_name .. " already exists.")
-  else
+	return
+  end
+	
   msg, code = download(base .. archive, archive, true)
   
   if msg ~= "OK" then
@@ -204,19 +207,14 @@ function download_llvm()
     
     error(msg)
   end
-  end
 
   -- extract the package
-  if os.isdir(pkg_name) then
-  	print("Directory " .. pkg_name .. " already exists.")
-  else
   if use_7zip then
     extract_7z(archive, pkg_name)
   else
     extract_tar_xz(archive, pkg_name)
   end
 end
-end
 
 function cmake(gen, conf, builddir, options)
     local cwd = os.getcwd()