usr.sbin/makefs: Sync with sys/vfs/hammer2

usr.sbin/makefs: Sync with sys/vfs/hammer2

Sync with following sys/vfs/hammer2 commits.

$ git log --pretty="%h %s" 185ae703d726eb41fe0f44e432a9575d06b2ba45.. -- sys/vfs/hammer2/
ae4718daaa sys/vfs/hammer2: Remove redundant "spmp->iroot = NULL;"
ee92f60939 sys/vfs/hammer2: Fix many comments
be41253d2a sys/vfs/hammer2: Rename HAMMER2_BREF_FLAG_ZERO -> HAMMER2_BREF_FLAG_UNUSED
64eadfb368 sys/vfs/hammer2: Fix incorrect reservedXXX names in ondisk structure
6feb58ab26 sys/vfs/hammer2: Minor cleanups for hammer2_disk.h
4b2ec0813c sys/vfs/hammer2: Move HAMMER2_{CHECK,COMP}_STRINGS to sbin/hammer2
cca587dd52 sys/vfs/hammer2: Move HAMMER2_METH_DEFAULT from hammer2_disk.h to hammer2.h
d21704d78e sys/vfs/hammer2: Fix a typo in a source code comment
fac0c41fdd sys/vfs/hammer2: Fix "already initialized" multi-volumes error message
6763396fd5 sys/vfs/hammer2: Remove redundant error check in hammer2_vfs_mount()
12757b74e2 sys/vfs/hammer2: Make fchain/vchain dump on last drop consistent
a011271d2d sys/vfs/hammer2: Remove comments on removed stuff
e6a1580946 sys/vfs/hammer2: Remove obsolete comment on HAMMER2_RESOLVE_RDONLY
e8e30c7644 sys/vfs/hammer2: Remove obsolete comment in hammer2_vop_readdir()
25b8f48546 sys/vfs/hammer2: #if0 hammer2_chain_lock_unhold()/hammer2_chain_unlock_hold()
b5513ad07d sys/vfs/hammer2: Use correct XOP struct in hammer2_xop_{lookup,delete}
5b691df11e sys/vfs/hammer2: hammer2_dump_chain() should belong to hammer2_chain.c
92931eab21 sys/vfs/hammer2: Use HAMMER2_PFSTYPE_NONE rather than 0
16f0b63d7f sys/vfs/hammer2: Make sure PFS exists after chain lookup on mount
4b0205e630 sys/vfs/hammer2: hammer2_ioctl_inode_{get,set} never returns error
634b6e30ca sys/vfs/hammer2: Add include guard for hammer2_xxhash.h
bc7ea12e61 sbin/hammer2: Remove HAMMER1 comment from dirhash()
47f63aa5d3 sys/vfs/hammer2: Rename hammer2_chain_core_init() -> hammer2_chain_init()
507074cda8 sys/vfs/hammer2: Change readonly purpose sysctls to CTLFLAG_RD
39b691836e sys/vfs/hammer2: Use __debugvar for RB_INSERT() result only used in KKASSERT
a4959f8900 sys/vfs/hammer2: Use __debugvar rather than trying to use it outside KASSERT
9944926ceb sys/vfs/hammer2: Avoid unused warning when !INVARIANTS