ddb: improve printing of inp_flags

Add four missing flags (INP_BINDANY, INP_INHASHLIST, INP_RESERVED_0,
INP_BOUNDFIB) used in inp_flags and remove one flag (INP_ORIGDSTADDR),
which is actually a flag used in inp_flags2 and not in inp_flags.

Reviewed by: markj
MFC after: 3 days
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D53498