iavf: clarify VLAN add/delete log messages and lower log level

iavf: clarify VLAN add/delete log messages and lower log level

The current dev_warn messages for too many VLAN changes are confusing
and one place incorrectly references "add" instead of "delete" VLANs
due to copy-paste errors.

- Use dev_info instead of dev_warn to lower the log level.
- Rephrase the message to: "virtchnl: Too many VLAN [add|delete]
  ([v1|v2]) requests; splitting into multiple messages to PF\n".

Suggested-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20251125223632.1857532-12-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>