Fix child info pipe fd leak when child process gets killed.

src/aof.c

@@ -221,6 +221,7 @@ static void killAppendOnlyChild(void) {
     server.aof_rewrite_time_start = -1;
     /* Close pipes used for IPC between the two processes. */
     aofClosePipes();
+    closeChildInfoPipe();
 }
 
 /* Called when the user switches from "appendonly yes" to "appendonly no"

src/db.c

@@ -451,6 +451,7 @@ void flushallCommand(client *c) {
     if (server.rdb_child_pid != -1) {
         kill(server.rdb_child_pid,SIGUSR1);
         rdbRemoveTempFile(server.rdb_child_pid);
+        closeChildInfoPipe();
     }
     if (server.saveparamslen > 0) {
         /* Normally rdbSave() will reset dirty, but we don't want this here

src/replication.c

@@ -1255,6 +1255,7 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
                     (long) server.rdb_child_pid);
             kill(server.rdb_child_pid,SIGUSR1);
             rdbRemoveTempFile(server.rdb_child_pid);
+            closeChildInfoPipe();
         }
 
         if (rename(server.repl_transfer_tmpfile,server.rdb_filename) == -1) {