Fix syntax error in patch application check

.github/workflows/build.yml

@@ -466,7 +466,7 @@ jobs:
           rm -rf IPv6_NAT_FIX.patch
 
           for p in *.patch; do
-            if patch -p1 --dry-run <"$p">
+            if patch -p1 --dry-run <"$p">; then
              echo "patch is OK, applying $p"
              patch -p1 < "$p"
              rm -f "$p"