User namespace xattrs are generally useful, and I think extN
is the only filesystem requiring a special mount option to
enable them, when xattrs are otherwise available.  So this
change sets that mount option into the defaults.

Note that if xattrs are config'd off, this will lead to a
mostly-harmless:

   EXT4-fs (sdc1): (no)user_xattr options not supported

message at mount time... 

Signed-off-by: Eric Sandeen <redacted>
---

diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index ff63a92..12a9452 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c

@@ -164,6 +164,7 @@ errcode_t ext2fs_initialize(const char *name, int flags,
 	set_field(s_raid_stripe_width, 0);	/* default stripe width: 0 */
 	set_field(s_log_groups_per_flex, 0);
 	set_field(s_flags, 0);
+	set_field(s_default_mount_opts, EXT2_DEFM_XATTR_USER);
 	if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
 		retval = EXT2_ET_UNSUPP_FEATURE;
 		goto cleanup;