ext4: Remove CONFIG_EXT4_FS_XATTR

Ted has sent out a RFC about removing this feature. Eric and Jan
confirmed that both RedHat and SUSE enable this feature in all their
product.  David also said that "As far as I know, it's enabled in all
Android kernels that use ext4."  So it seems OK for us.

And what's more, as inline data depends its implementation on xattr,
and to be frank, I don't run any test again inline data enabled while
xattr disabled.  So I think we should add inline data and remove this
config option in the same release.

[ The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which
  isn't much in the grand scheme of things.  Since no one seems to be
  testing this configuration except for some automated compile farms, on
  balance we are better removing this config option, and so that it is
  effectively always enabled. -- tytso ]

Cc: David Brown <davidb@codeaurora.org>
Cc: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/Kconfig

@@ -39,22 +39,8 @@ config EXT4_USE_FOR_EXT23
 	  compiled kernel size by using one file system driver for
 	  ext2, ext3, and ext4 file systems.
 
-config EXT4_FS_XATTR
-	bool "Ext4 extended attributes"
-	depends on EXT4_FS
-	default y
-	help
-	  Extended attributes are name:value pairs associated with inodes by
-	  the kernel or by users (see the attr(5) manual page, or visit
-	  <http://acl.bestbits.at/> for details).
-
-	  If unsure, say N.
-
-	  You need this for POSIX ACL support on ext4.
-
 config EXT4_FS_POSIX_ACL
 	bool "Ext4 POSIX Access Control Lists"
-	depends on EXT4_FS_XATTR
 	select FS_POSIX_ACL
 	help
 	  POSIX Access Control Lists (ACLs) support permissions for users and
@@ -67,7 +53,6 @@ config EXT4_FS_POSIX_ACL
 
 config EXT4_FS_SECURITY
 	bool "Ext4 Security Labels"
-	depends on EXT4_FS_XATTR
 	help
 	  Security labels support alternative access control models
 	  implemented by security modules like SELinux.  This option