qed: Prevent stack corruption on MFW interaction

qed: Prevent stack corruption on MFW interaction

Orabug: 25477939

Driver uses a union for copying data to & from management firmware
when interacting with it.
Problem is that the function always copies sizeof(union) while commit
2edbff8dcb5d ("qed: Learn resources from management firmware") is casting
a union elements which is of smaller size [24-byte instead of 88-bytes].

Also, the union contains some inappropriate elements which increase its
size [should have been 32-bytes]. While this shouldn't corrupt other
PF messages to the MFW [as management firmware enforces permissions so
that each PF is allowed to write only to its own mailbox] we fix this
here as well.

Fixes: 2edbff8dcb5d ("qed: Learn resources from management firmware")
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit bb48024284327768debd03a197d7c4179ec6ca05)
Signed-off-by: Brian Maly <brian.maly@oracle.com>