trim() modifies the string in place if needed and returns a pointer to
the end of the resulting string. Update udhcp_str2optset() so it no
longer sets the value of 'val' to the return value of trim().
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>