sdl12-compat: CI: Fixed wrong tag name for actions/checkout@v2

SDL Commits
1 
From a122f24bde4fdf7e8b8aea3dffb1e50f0112ae04 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Tue, 1 Jun 2021 18:02:10 -0400
Subject: [PATCH] CI: Fixed wrong tag name for actions/checkout@v2

---
 .github/workflows/main.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 47d3faa..86b66e3 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -21,7 +21,7 @@ jobs:
     - name: Get SDL2 headers
       uses: actions/checkout@v2
       with:
-        name: libsdl-org/SDL
+        repository: libsdl-org/SDL
         ref: release-2.0.14
         path: SDL2
     - name: Get sdl12-compat sources