OS X: check for SDL framework before SDL library

SConscript

@@ -238,13 +238,11 @@ def findLibs(env, conf):
 	if not GetOption('renderer'):
 		#Look for SDL
 		runSdlConfig = platform == "Linux" or compilePlatform == "Linux"
-		if not conf.CheckLib("SDL"):
-			if platform == "Darwin":
-				if not conf.CheckFramework("SDL"):
-					FatalError("SDL framework not found or not installed")
-				runSdlConfig = False
-			else:
-				FatalError("SDL development library not found or not installed")
+		if platform == "Darwin" and conf.CheckFramework("SDL"):
+			runSdlConfig = False
+		elif not conf.CheckLib("SDL"):
+			FatalError("SDL development library not found or not installed")
+
 		if runSdlConfig:
 			try:
 				env.ParseConfig('sdl-config --cflags')