scons: Set default LIBS env var.
diff --git a/scons/gallium.py b/scons/gallium.py
index b3e48ab..43603e5 100644
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -414,6 +414,9 @@
         ]
     env.Append(LINKFLAGS = linkflags)
 
+    # Default libs
+    env.Append(LIBS = [])
+
     # Custom builders and methods
     createConvenienceLibBuilder(env)
     createCodeGenerateMethod(env)