net/mlx4: Fix memory corruption in mlx4_MAD_IFC_wrapper

Fix a memory corruption at mlx4_MAD_IFC_wrapper.

A table of size dev->caps.pkey_table_len[port]*sizeof(*table)
was allocated, but get_full_pkey_table() assumes that the number
of entries in the table is a multiplication of 32 (which isn't always
correct).

Fixes: 0a9a0188 ('mlx4: MAD_IFC paravirtualization')
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>