fstyp: move sys/ include path after zfs include paths

The reason is that FreeBSD refcount.h shadows ZFS refcount.h and that
will lead to a build error after a planned import of the ARC buf data
scatter-ization.
It's possible that some day we will have an opposite problem where
a ZFS header would shadow an essential FreeBSD header.
So, we need to think about a better long term solution.

Discussed with:	allanjude
MFC after:	17 days

usr.sbin/fstyp/Makefile

@@ -19,8 +19,6 @@ WARNS?=	2
 SUBDIR+=	tests
 .endif
 
-CFLAGS+=-I${SRCTOP}/sys
-
 .if ${MK_ZFS} != "no"
 IGNORE_PRAGMA=  YES
 
@@ -36,6 +34,8 @@ CFLAGS+= -I${SRCTOP}/sys/cddl/contrib/opensolaris/uts/common/sys
 CFLAGS+= -I${SRCTOP}/cddl/contrib/opensolaris/head
 .endif
 
+CFLAGS+=-I${SRCTOP}/sys
+
 LIBADD=	geom md
 
 .if ${MK_ZFS} != "no"