Revert "lib: build list_sort() only if needed"

This reverts commit a069c266ae.

It turns ou that not only was it missing a case (XFS) that needed it,
but perhaps more importantly, people sometimes want to enable new
modules that they hadn't had enabled before, and if such a module uses
list_sort(), it can't easily be inserted any more.

So rather than add a "select LIST_SORT" to the XFS case, just leave it
compiled in.  It's not all _that_ big, after all, and the inconvenience
isn't worth it.

Requested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ubifs/Kconfig

@@ -7,7 +7,6 @@ config UBIFS_FS
 	select CRYPTO if UBIFS_FS_ZLIB
 	select CRYPTO_LZO if UBIFS_FS_LZO
 	select CRYPTO_DEFLATE if UBIFS_FS_ZLIB
-	select LIST_SORT
 	depends on MTD_UBI
 	help
 	  UBIFS is a file system for flash devices which works on top of UBI.