OS-5083 lx_proc /proc/swaps needs to try harder

*** 3897,3906 ****
--- 3897,3909 ----
   * lxpr_read_swaps():
   *
   * We don't support swap files or partitions, but some programs like to look
   * here just to check we have some swap on the system, so we lie and show
   * our entire swap cap as one swap partition.
+  *
+  * It is important to use formatting identical to the Linux implementation
+  * so that consumers do not break. See swap_show() in mm/swapfile.c.
   */
  /* ARGSUSED */
  static void
  lxpr_read_swaps(lxpr_node_t *lxpnp, lxpr_uiobuf_t *uiobuf)
  {
*** 3912,3924 ****
          totswap = zone->zone_max_swap_ctl >> 10;
          usedswap = zone->zone_max_swap >> 10;
          mutex_exit(&zone->zone_mem_lock);
  
          lxpr_uiobuf_printf(uiobuf,
!             "Filename                                "
!             "Type            Size    Used    Priority\n");
!         lxpr_uiobuf_printf(uiobuf, "%-40s%-16s%-8llu%-8llu%-8d\n",
              "/dev/swap", "partition", totswap, usedswap, -1);
  }
  
  /*
   * inotify tunables exported via /proc.
--- 3915,3926 ----
          totswap = zone->zone_max_swap_ctl >> 10;
          usedswap = zone->zone_max_swap >> 10;
          mutex_exit(&zone->zone_mem_lock);
  
          lxpr_uiobuf_printf(uiobuf,
!             "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
!         lxpr_uiobuf_printf(uiobuf, "%-40s%s\t%llu\t%llu\t%d\n",
              "/dev/swap", "partition", totswap, usedswap, -1);
  }
  
  /*
   * inotify tunables exported via /proc.