size and usage in hrStorageAllocationUnits. If the file system has
more than 2^31 allocations it can not be shown correctly and the
meters are useless.
In such cases follow net-snmp behaviour and increase
hrStorageAllocationUnits so the values fit under INT_MAX.
PR: bin/177183
Submitted by: Eugene Grosbein egrosbein rdtc.ru
MFC after: 2 weeks