Build failures after recent chfs update

[Adam Ciarciński <adam%NetBSD.org@localhost>]

Greetings,

Recent changes to makefs make building on Mac OS X fail:

---cut---
/Users/adam/dist/src/tools/makefs/../../usr.sbin/makefs/chfs/chfs_mkfs.c:212:43:
 error: 
      no member named 'st_mtimensec' in 'struct stat'; did you mean
      'st_mtimespec'?
        fdirent.mctime = htole32(node->inode->st.st_mtimensec);
                                                 ^~~~~~~~~~~~
                                                 st_mtimespec
---cut---

st_mtimensec is not defined on Darwin, unless _POSIX_C_SOURCE is defined. But 
if I define _POSIX_C_SOURCE (in compat), other issues show up. I propose the 
following change:

diff -u -r1.3 chfs_mkfs.c
--- chfs_mkfs.c 19 Apr 2012 17:28:26 -0000      1.3
+++ chfs_mkfs.c 20 Apr 2012 12:03:20 -0000
@@ -209,7 +209,11 @@
        }
 
        fdirent.version = htole64(version++);
+#ifdef HAVE_STRUCT_STAT_ST_MTIMENSEC
        fdirent.mctime = htole32(node->inode->st.st_mtimensec);
+#else
+       fdirent.mctime = htole32(node->inode->st.st_mtimespec.tv_nsec);
+#endif
        fdirent.nsize = htole32(strlen(name));
        fdirent.dtype = htole32(IFTOCHT(node->type & S_IFMT));
        fdirent.name_crc = htole32(crc32(0, (uint8_t *)name, fdirent.nsize));

Also:

diff -u -r1.1 Makefile.inc
--- chfs/Makefile.inc   19 Apr 2012 15:36:06 -0000      1.1
+++ chfs/Makefile.inc   20 Apr 2012 12:06:33 -0000
@@ -5,5 +5,7 @@
 CPPFLAGS+= -I${CHFS}
 
 SRCS+= chfs_mkfs.c
+.if !defined(HOSTPROG)
 LDADD+= -lz
 DPADD+= ${LIBZ}
+.endif

May I commit these changes?

Kind regards,
Adam