Revert "linux-user: fix compat with glibc >= 2.36 sys/mount.h"

This reverts commit 3cd3df2.

glibc has fixed (in 2.36.9000-40-g774058d729) the problem
that caused a clash when both sys/mount.h annd linux/mount.h
are included, and backported this to the 2.36 stable release
too:

  https://sourceware.org/glibc/wiki/Release/2.36#Usage_of_.3Clinux.2Fmount.h.3E_and_.3Csys.2Fmount.h.3E

It is saner for QEMU to remove the workaround it applied for
glibc 2.36 and expect distros to ship the 2.36 maint release
with the fix. This avoids needing to add a further workaround
to QEMU to deal with the fact that linux/brtfs.h now also pulls
in linux/mount.h via linux/fs.h since Linux 6.1

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230110174901.2580297-3-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/syscall.c

@@ -95,25 +95,7 @@
 #include <linux/soundcard.h>
 #include <linux/kd.h>
 #include <linux/mtio.h>
-
-#ifdef HAVE_SYS_MOUNT_FSCONFIG
-/*
- * glibc >= 2.36 linux/mount.h conflicts with sys/mount.h,
- * which in turn prevents use of linux/fs.h. So we have to
- * define the constants ourselves for now.
- */
-#define FS_IOC_GETFLAGS                _IOR('f', 1, long)
-#define FS_IOC_SETFLAGS                _IOW('f', 2, long)
-#define FS_IOC_GETVERSION              _IOR('v', 1, long)
-#define FS_IOC_SETVERSION              _IOW('v', 2, long)
-#define FS_IOC_FIEMAP                  _IOWR('f', 11, struct fiemap)
-#define FS_IOC32_GETFLAGS              _IOR('f', 1, int)
-#define FS_IOC32_SETFLAGS              _IOW('f', 2, int)
-#define FS_IOC32_GETVERSION            _IOR('v', 1, int)
-#define FS_IOC32_SETVERSION            _IOW('v', 2, int)
-#else
 #include <linux/fs.h>
-#endif
 #include <linux/fd.h>
 #if defined(CONFIG_FIEMAP)
 #include <linux/fiemap.h>

meson.build

@@ -2046,8 +2046,6 @@ config_host_data.set('HAVE_OPTRESET',
                      cc.has_header_symbol('getopt.h', 'optreset'))
 config_host_data.set('HAVE_IPPROTO_MPTCP',
                      cc.has_header_symbol('netinet/in.h', 'IPPROTO_MPTCP'))
-config_host_data.set('HAVE_SYS_MOUNT_FSCONFIG',
-                     cc.has_header_symbol('sys/mount.h', 'FSCONFIG_SET_FLAG'))
 
 # has_member
 config_host_data.set('HAVE_SIGEV_NOTIFY_THREAD_ID',