Revert "add code to debug log levels (later)"

This reverts commit 1e5067d3fd870dab6a70917fa8364749cf0ee98f.

Conflicts:
	log.c
Add compiler attributes to type check format strings

Conflicts:
	log.c
	log.h
Fix format string warnings

recv.c: In function ‘recv_rs_ra’:
recv.c:80:5: warning: format ‘%d’ expects argument of type ‘int’, but
argument 3 has type ‘size_t’ [-Wformat=]
     flog(LOG_ERR, "received a bogus IPV6_HOPLIMIT from the kernel!
     len=%d, data=%d", cmsg->cmsg_len, *(int *)CMSG_DATA(cmsg));
          ^
          recv.c:90:35: warning: format ‘%d’ expects argument of type
          ‘int’, but argument 3 has type ‘size_t’ [-Wformat=]
                    cmsg->cmsg_len, ((struct in6_pktinfo
                    *)CMSG_DATA(cmsg))->ipi6_ifindex);