net/mlx5: Fix return code in case of hyperv wrong size read

Return code value could be non deterministic in case of wrong size read.
With this patch, if such error occurs, set rc to be -EIO.

In addition, mlx5_hv_config_common() supports reading of
HV_CONFIG_BLOCK_SIZE_MAX bytes only, fix to early return error with
bad input.

Fixes: 913d14e86657 ("net/mlx5: Add wrappers for HyperV PCIe operations")
Reported-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5: Add wrappers for HyperV PCIe operations

Add wrapper functions for HyperV PCIe read / write /
block_invalidate_register operations. This will be used as an
infrastructure in the downstream patch for software communication.

This will be enabled by default if CONFIG_PCI_HYPERV_INTERFACE is set.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>