Update rcore.c comment (#5700)

src/rcore.c

@@ -1227,7 +1227,7 @@ void UnloadVrStereoConfig(VrStereoConfig config)
 //----------------------------------------------------------------------------------
 
 // Load shader from files and bind default locations
-// NOTE: If shader string is NULL, using default vertex/fragment shaders
+// NOTE: If shader filename is NULL, using default vertex/fragment shaders
 Shader LoadShader(const char *vsFileName, const char *fsFileName)
 {
     Shader shader = { 0 };