VFS: Handle lazytime in do_mount()

Since commit e462ec50 ("VFS: Differentiate mount flags (MS_*) from
internal superblock flags") the lazytime mount option doesn't get passed
on anymore.

Fix the issue by handling the option in do_mount().
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/namespace.c

@@ -2826,6 +2826,7 @@ long do_mount(const char *dev_name, const char __user *dir_name,
 			    SB_DIRSYNC |
 			    SB_SILENT |
 			    SB_POSIXACL |
+			    SB_LAZYTIME |
 			    SB_I_VERSION);
 
 	if (flags & MS_REMOUNT)