Add mode to open call with O_CREAT

Change-Id: I63eb3d5499ae7e9ff9a77393763e39b747fd4611
diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index 3bcbbc4..b9ee0ef 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -1121,7 +1121,7 @@
             fflush(stdout);
             int outFd = STDOUT_FILENO;
             if (g_outputFile) {
-                outFd = open(g_outputFile, O_WRONLY | O_CREAT);
+                outFd = open(g_outputFile, O_WRONLY | O_CREAT, 0644);
             }
             if (outFd == -1) {
                 printf("Failed to open '%s', err=%d", g_outputFile, errno);