Valgrind: another complaint about uninitialized bytes.

src/os/unix/ngx_channel.c

diff --git a/src/os/unix/ngx_channel.c b/src/os/unix/ngx_channel.c
index 29c69da..536a9ed 100644
--- a/src/os/unix/ngx_channel.c
+++ b/src/os/unix/ngx_channel.c
@@ -34,6 +34,8 @@
         msg.msg_control = (caddr_t) &cmsg;
         msg.msg_controllen = sizeof(cmsg);
 
+        ngx_memzero(&cmsg, sizeof(cmsg));
+
         cmsg.cm.cmsg_len = CMSG_LEN(sizeof(int));
         cmsg.cm.cmsg_level = SOL_SOCKET;
         cmsg.cm.cmsg_type = SCM_RIGHTS;