Cisco Nexus 9000 series report old version number

[Ichabond]

Description of Issue/Question

Did you follow the steps from https://github.com/napalm-automation/napalm#faq

(Place an x between the square brackets where applicable)

• Yes
• [] No

Setup

napalm version

2.4.0

Network operating system version

(Paste verbatim output from show version - or equivalent - between quotes below)

Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Copyright (C) 2002-2019, Cisco and/or its affiliates.
All rights reserved.
The copyrights to certain works contained in this software are
owned by other third parties and used and distributed under their own
licenses, such as open source.  This software is provided "as is," and unless
otherwise stated, there is no warranty, express or implied, including but not
limited to warranties of merchantability and fitness for a particular purpose.
Certain components of this software are licensed under
the GNU General Public License (GPL) version 2.0 or 
GNU General Public License (GPL) version 3.0  or the GNU
Lesser General Public License (LGPL) Version 2.1 or 
Lesser General Public License (LGPL) Version 2.0. 
A copy of each such license is available at
http://www.opensource.org/licenses/gpl-2.0.php and
http://opensource.org/licenses/gpl-3.0.html and
http://www.opensource.org/licenses/lgpl-2.1.php and
http://www.gnu.org/licenses/old-licenses/library.txt.

Software
  BIOS: version 07.65
  NXOS: version 7.0(3)I7(6)
  BIOS compile time:  09/04/2018
  NXOS image file is: bootflash:///nxos.7.0.3.I7.6.bin
  NXOS compile time:  3/5/2019 13:00:00 [03/05/2019 22:04:55]


Hardware
  cisco Nexus9000 93180YC-EX chassis 
  Intel(R) Xeon(R) CPU  @ 1.80GHz with 24633600 kB of memory.
  Processor Board ID FDO2338098Y

  Device name: sw03.dus01
  bootflash:   53298520 kB
Kernel uptime is 39 day(s), 13 hour(s), 30 minute(s), 10 second(s)

Last reset at 449026 usecs after Fri Mar  6 02:25:49 2020
  Reason: Reset due to upgrade
  System version: 9.2(2)
  Service: 

plugin
  Core Plugin, Ethernet Plugin

Active Package(s):

Steps to Reproduce the Issue

Downgrade a switch. grains.get version will report the previous version.

As seen in the above, this switch will report its version is 9.2(2), even though it's running 7.0(3)I7(6). This is due to the use of rr_sys_ver` which reports the system version before the reboot.

Patch incoming.