lib: build list_sort() only if needed

Build list_sort() only for configs that need it -- those that don't save
~581 bytes (i386).

Signed-off-by: Don Mullis <don.mullis@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/Kconfig

@@ -9,6 +9,7 @@ menuconfig DRM
 	depends on (AGP || AGP=n) && PCI && !EMULATED_CMPXCHG && MMU
 	select I2C
 	select I2C_ALGOBIT
+	select LIST_SORT
 	help
 	  Kernel-level support for the Direct Rendering Infrastructure (DRI)
 	  introduced in XFree86 4.0. If you say Y here, you need to select

fs/ubifs/Kconfig

@@ -7,6 +7,7 @@ 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.

lib/Kconfig

@@ -160,6 +160,9 @@ config TEXTSEARCH_BM
 config TEXTSEARCH_FSM
 	tristate
 
+config LIST_SORT
+	boolean
+
 config HAS_IOMEM
 	boolean
 	depends on !NO_IOMEM

lib/Makefile

@@ -21,7 +21,7 @@ lib-y	+= kobject.o kref.o klist.o
 
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
-	 string_helpers.o gcd.o list_sort.o
+	 string_helpers.o gcd.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG
@@ -40,6 +40,7 @@ lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o
 lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
 obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
 obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
+obj-$(CONFIG_LIST_SORT) += list_sort.o
 obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o
 obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
 obj-$(CONFIG_DEBUG_LIST) += list_debug.o