sys_sysfs: Add CONFIG_SYSFS_SYSCALL

sys_sysfs is an obsolete system call no longer supported by libc.

 - This patch adds a default CONFIG_SYSFS_SYSCALL=y

 - Option can be turned off in expert mode.

 - cond_syscall added to kernel/sys_ni.c

[akpm@linux-foundation.org: tweak Kconfig help text]
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/filesystems.c b/fs/filesystems.c
index 92567d9..5797d45 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -121,6 +121,7 @@
 
 EXPORT_SYMBOL(unregister_filesystem);
 
+#ifdef CONFIG_SYSFS_SYSCALL
 static int fs_index(const char __user * __name)
 {
 	struct file_system_type * tmp;
@@ -199,6 +200,7 @@
 	}
 	return retval;
 }
+#endif
 
 int __init get_filesystem_list(char *buf)
 {