Auto-mounter: Fix state setting. Not harmful other than it can cause a debug...

Auto-mounter:  Fix state setting.  Not harmful other than it can cause a debug assertion to fire if you manually unmount the media before removing it which is, of course, what you are supposed to do.

fs/fs_automount.c

@@ -328,14 +328,15 @@ static int automount_unmount(FAR struct automounter_state_s *priv)
             }
         }
 
-      /* Successfully unmounted */
-
-      priv->mounted = false;
-      return OK;
+      /* Fall through */
 
     case OK_NOENT:
-      /* I suppose this is okay */
+      /* The mountpoint is not present.  This is normal behavior in the
+       * case where the user manually un-mounted the volume before removing
+       * media.  Nice job, Mr. user.
+       */
 
+      priv->mounted = false;
       return OK;
 
     default: