zfs: attach zpool_influxdb to build

From the zpool_influxdb.8 manual page:
  zpool_influxdb produces InfluxDB-line-protocol-compatible metrics from
  zpools.  Like the zpool command, zpool_influxdb reads the current pool
  status and statistics.  Unlike the zpool command which is intended for
  humans, zpool_influxdb formats the output in the InfluxDB line protocol.
  The expected use is as a plugin to a metrics collector or aggregator,
  such as Telegraf.

zpool_influxdb is installed into /usr/libexec/zfs/

Differential revision:	https://reviews.freebsd.org/D31094
MFC after:	3 days

cddl/Makefile

@@ -3,7 +3,7 @@
 .include <src.opts.mk>
 
 SUBDIR=	lib .WAIT \
-	sbin share usr.bin usr.sbin
+	sbin share usr.bin usr.libexec usr.sbin
 
 SUBDIR.${MK_TESTS}+= tests
 

cddl/usr.libexec/Makefile

@@ -0,0 +1,13 @@
+# $FreeBSD$
+
+.include <src.opts.mk>
+
+SUBDIR=	${_zpool_influxdb}
+
+.if ${MK_ZFS} != "no"
+_zpool_influxdb= zpool_influxdb
+.endif
+
+SUBDIR_PARALLEL=
+
+.include <bsd.subdir.mk>

cddl/usr.libexec/zpool_influxdb/Makefile

@@ -0,0 +1,28 @@
+# $FreeBSD$
+
+ZFSTOP=	${SRCTOP}/sys/contrib/openzfs
+
+.PATH: ${ZFSTOP}/cmd/zpool_influxdb
+.PATH: ${ZFSTOP}/man/man8
+
+PROG=	zpool_influxdb
+MAN=	zpool_influxdb.8
+BINDIR?=	/usr/libexec/zfs
+
+WARNS?=	0
+CSTD=	c99
+
+CFLAGS+= \
+	-DIN_BASE \
+	-I${ZFSTOP}/include \
+	-I${ZFSTOP}/lib/libspl/include \
+	-I${ZFSTOP}/lib/libspl/include/os/freebsd \
+	-include ${ZFSTOP}/include/os/freebsd/spl/sys/ccompile.h \
+	-DHAVE_ISSETUGID \
+	-include ${SRCTOP}/sys/modules/zfs/zfs_config.h \
+	-DSYSCONFDIR=\"/etc\" \
+	-DPKGDATADIR=\"/usr/share/zfs\"
+
+LIBADD=	nvpair spl zfs
+
+.include <bsd.prog.mk>

cddl/usr.libexec/zpool_influxdb/Makefile.depend

@@ -0,0 +1,31 @@
+# $FreeBSD$
+# Autogenerated - do NOT edit!
+
+DIRDEPS = \
+	cddl/lib/libavl \
+	cddl/lib/libnvpair \
+	cddl/lib/libumem \
+	cddl/lib/libuutil \
+	cddl/lib/libzfs \
+	cddl/lib/libzfs_core \
+	gnu/lib/csu \
+	include \
+	include/xlocale \
+	lib/${CSU_DIR} \
+	lib/libc \
+	lib/libcompiler_rt \
+	lib/libexpat \
+	lib/libgeom \
+	lib/libmd \
+	lib/libsbuf \
+	lib/libthr \
+	lib/libutil \
+	lib/libz \
+	lib/msun \
+
+
+.include <dirdeps.mk>
+
+.if ${DEP_RELDIR} == ${_DEP_RELDIR}
+# local dependencies - needed for -jN in clean tree
+.endif

etc/mtree/BSD.debug.dist

@@ -54,6 +54,8 @@
                 ..
                 sm.bin
                 ..
+                zfs
+                ..
             ..
             sbin
             ..

etc/mtree/BSD.usr.dist

@@ -156,6 +156,8 @@
         ..
         sm.bin
         ..
+        zfs
+        ..
     ..
     local
     ..