sysctl extern cleanup: sg

Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move sg_big_buff extern declaration to scsi/sg.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Doug Gilbert <dgilbert@interlog.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/scsi/sg.h b/include/scsi/sg.h
index 934ae38..a9f3c6f 100644
--- a/include/scsi/sg.h
+++ b/include/scsi/sg.h
@@ -70,6 +70,9 @@
  (for the lk 2.2 series).
 */
 
+#ifdef __KERNEL__
+extern int sg_big_buff; /* for sysctl */
+#endif
 
 /* New interface introduced in the 3.x SG drivers follows */