add descriptive comment for TIF_MEMDIE task flag declaration.

Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index e9a5614..02560fd8 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -98,7 +98,7 @@
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
 #define TIF_POLLING_NRFLAG	3	/* true if poll_idle() is polling
 					   TIF_NEED_RESCHED */
-#define TIF_MEMDIE		4
+#define TIF_MEMDIE		4	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
 #define TIF_FREEZE		6	/* is freezing for suspend */
 #define TIF_IRQ_SYNC		7	/* sync pipeline stage */