Use mj_versionString to report version in dm_control.

PiperOrigin-RevId: 495358583
Change-Id: Iaf46c920ace89aa7e680007862c7348cc317e000

Author: saran-t

dm_control/mujoco/wrapper/mjbindings/__init__.py

@@ -28,7 +28,7 @@
 try:
   from dm_control.mujoco.wrapper.mjbindings import functions
   from dm_control.mujoco.wrapper.mjbindings.functions import mjlib
-  logging.info('MuJoCo library version is: %d', mjlib.mj_version())
+  logging.info('MuJoCo library version is: %s', mjlib.mj_versionString())
   # Internal analytics.
 except (IOError, OSError):
   logging.warning('mjbindings failed to import mjlib and other functions. '