mesa: Fix misplaced #endif

If FEATURE_texture_s3tc is not defined, FXT1 formats would erroneously
fall through to the MESA_FORMAT_RGBA_FLOAT32 case.

src/mesa/main/formats.c

@@ -1338,12 +1338,12 @@ _mesa_format_to_type_and_comps(gl_format format,
    case MESA_FORMAT_SRGBA_DXT1:
    case MESA_FORMAT_SRGBA_DXT3:
    case MESA_FORMAT_SRGBA_DXT5:
+#endif
 #endif
       /* XXX generate error instead? */
       *datatype = GL_UNSIGNED_BYTE;
       *comps = 0;
       return;
-#endif
 
    case MESA_FORMAT_RGBA_FLOAT32:
       *datatype = GL_FLOAT;