[libsmi] Missing warning

HI,

I'm doing some cleanups of sme MIB modules. In them are many examples of tables that have a RowStatus column (with no restriction of values) and have MAX-ACCESS of "read-write" on the columns. I was expecting to see a warning that "read-create" should have been used instead of "read-write". If this warning is presently generated, I suggest that it be added.

Regards, /david t. perkins