net/mlx5: Avoid "No data available" when FW version queries fail

net/mlx5: Avoid "No data available" when FW version queries fail

Avoid printing the misleading "kernel answers: No data available" devlink
output when querying firmware or pending firmware version fails
(e.g. MLX5 fw state errors / flash failures).

FW can fail on loading the pending flash image and get its version due
to various reasons, examples:

mlxfw: Firmware flash failed: key not applicable, err (7)
mlx5_fw_image_pending: can't read pending fw version while fw state is 1

and the resulting:
$ devlink dev info
kernel answers: No data available

Instead, just report 0 or 0xfff.. versions in case of failure to indicate
a problem, and let other information be shown.

after the fix:
$ devlink dev info
pci/0000:00:06.0:
  driver mlx5_core
  serial_number xxx...
  board.serial_number MT2225300179
  versions:
      fixed:
        fw.psid MT_0000000436
      running:
        fw.version 22.41.0188
        fw 22.41.0188
      stored:
        fw.version 255.255.65535
        fw 255.255.65535

Fixes: 9c86b07e3069 ("net/mlx5: Added fw version query command")
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260330194015.53585-3-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>