DLM must depend on SYSFS

The dependency of DLM on SYSFS got lost in
commit 6ed7257b46 resulting in the
following compile error with CONFIG_DLM=y, CONFIG_SYSFS=n:

<--  snip  -->

...
  LD      .tmp_vmlinux1
fs/built-in.o: In function `dlm_lockspace_init':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/dlm/lockspace.c:231: undefined reference to `kernel_subsys'
fs/built-in.o: In function `configfs_init':
/home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/configfs/mount.c:143: undefined reference to `kernel_subsys'
make[1]: *** [.tmp_vmlinux1] Error 1

<--  snip  -->

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/dlm/Kconfig

@@ -3,7 +3,7 @@ menu "Distributed Lock Manager"
 
 config DLM
 	tristate "Distributed Lock Manager (DLM)"
-	depends on IPV6 || IPV6=n
+	depends on SYSFS && (IPV6 || IPV6=n)
 	select CONFIGFS_FS
 	select IP_SCTP
 	help