silc_bit_fnz
SYNOPSIS
int silc_bit_fnz(volatile unsigned long *bitmap, SilcUInt32 bitmap_size, SilcUInt32 offset);
DESCRIPTION
Returns the bit number of the next zero bit in the `bitmap' of size of `bitmap_size' starting at bit `offset'. Returns -1 on error or when there were no more zero bits and sets silc_errno.