net/mlx5e: Fix wrong return value on ioctl EEPROM query failure

commit 0b894297 upstream.

The ioctl EEPROM query wrongly returns success on read failures, fix
that by returning the appropriate error code.

Fixes: bb64143e

 ("net/mlx5e: Add ethtool support for dump module EEPROM")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>