Typecast to silence a compiler warning:

row/row0sel.c: 4548
        C4244: '=' : conversion from 'float' to 'ib_ulonglong', possible loss of data
row/row0sel.c: 4553
        C4244: '=' : conversion from 'double' to 'ib_ulonglong', possible loss of data

Reported by:	Jonas Oreland <Jonas.Oreland@Sun.COM>
Discussed with:	Sunny Bains <sunny.bains@oracle.com>