avr32: need to clear RESTORE_SIGMASK on successful signal delivery

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c
index a4855ae..ae386c3 100644
--- a/arch/avr32/kernel/signal.c
+++ b/arch/avr32/kernel/signal.c
@@ -247,6 +247,7 @@
 	 * Block the signal if we were successful.
 	 */
 	block_sigmask(ka, sig);
+	clear_thread_flag(TIF_RESTORE_SIGMASK);
 }
 
 /*