alpha: wire up accept4 syscall

Somehow wiring up the accept4 syscall on Alpha was missed long ago.
This commit rectifies that oversight.

Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/alpha/kernel/systbls.S b/arch/alpha/kernel/systbls.S
index 6acea1f..53d0ce2 100644
--- a/arch/alpha/kernel/systbls.S
+++ b/arch/alpha/kernel/systbls.S
@@ -520,6 +520,7 @@
 	.quad sys_clock_adjtime
 	.quad sys_syncfs			/* 500 */
 	.quad sys_setns
+	.quad sys_accept4
 
 	.size sys_call_table, . - sys_call_table
 	.type sys_call_table, @object