first part of a verifier is set to the first IP address from
V_in_ifaddrhead list. This address is typically the loopback address
making the first part of the verifier practically non-unique. The second
part of the verifier is initialized to zero making its initial value
non-unique too.
This commit changes the strategy for create verifier initialization:
just initialize it to a random value. Also move verifier handling into
its own function and use a mutex to protect the variable.
This change is a candidate for porting to sys/nfsclient.
Reviewed by: jhb, rmacklem
Approved by: trasz (mentor)
2727bc045c