pcp: fix win32 warning
@@ -84,7 +84,7 @@ int pcp_option_encode(struct mbuf *mb, enum pcp_option_code code,
mb->pos = start - 4;
err |= mbuf_write_u8(mb, code);
err |= mbuf_write_u8(mb, 0x00);
- err |= mbuf_write_u16(mb, htons(len));
+ err |= mbuf_write_u16(mb, htons((uint16_t)len));
mb->pos += len;
/* padding */
