Rename refcount.h to zfs_refcount.h

Renamed to avoid conflicting with refcount.h when a different
implementation is already provided by the platform.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10620

include/os/freebsd/spl/sys/ccompile.h

@@ -119,7 +119,7 @@ extern "C" {
 #define	__CONST			__sun_attr__((__const__))
 #define	__PURE			__sun_attr__((__pure__))
 
-#ifdef INVARIANTS
+#if defined(INVARIANTS) && !defined(ZFS_DEBUG)
 #define	ZFS_DEBUG
 #undef 	NDEBUG
 #endif

include/os/freebsd/spl/sys/file.h

@@ -30,7 +30,6 @@
 #define	_OPENSOLARIS_SYS_FILE_H_
 
 #include <sys/refcount.h>
-#include_next <sys/refcount.h>
 #include_next <sys/file.h>
 
 #define	FKIOCTL	0x80000000	/* ioctl addresses are from kernel */

include/os/freebsd/spl/sys/vnode.h

@@ -53,7 +53,7 @@ enum symfollow { NO_FOLLOW = NOFOLLOW };
 #include <sys/mount.h>
 #include <sys/cred.h>
 #include <sys/fcntl.h>
-#include_next <sys/refcount.h>
+#include <sys/refcount.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>
 #include <sys/syscallsubr.h>