Linux 6.17 compat: Fix broken projectquota on 6.17

We need to specifically use the FX_XFLAG_* macros in zpl_ioctl_*attr()
codepaths, and the FS_*_FL macros in the zpl_ioctl_*flags() codepaths.
The earlier code just assumes the FS_*_FL macros for both codepaths.
The 6.17 kernel add a bitmask check in copy_fsxattr_from_user() that
exposed this error via failing 'projectquota' ZTS tests.

Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #17884
Closes #17869

lib/libspl/include/Makefile.am

@@ -78,6 +78,7 @@ libspl_sys_HEADERS += \
 	%D%/os/linux/sys/param.h \
 	%D%/os/linux/sys/stat.h \
 	%D%/os/linux/sys/sysmacros.h \
+	%D%/os/linux/sys/vfs.h \
 	%D%/os/linux/sys/zfs_context_os.h
 
 libspl_ia32_HEADERS = \

lib/libspl/include/os/linux/sys/vfs.h

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/* Copyright 2025 by Lawrence Livermore National Security, LLC. */
+
+/* This is the Linux userspace version of include/os/linux/spl/sys/vfs.h */
+
+#ifndef	_LIBSPL_SYS_VFS_H
+#define	_LIBSPL_SYS_VFS_H
+
+#include <linux/fs.h>
+#include <sys/statfs.h>
+
+#endif