Add mode when open(O_CREAT) is used.

When creating a new file using open(..., O_CREAT), it is an error
to fail to specify a creation mode. If a mode is not specified, a
random stack provided value is used as the "mode".

This will become a compile error in a future Android change.

Change-Id: I73c1e1a39ca36bf01704b07302af4971d234b5a8
diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
index 00004e9..488fd8c 100644
--- a/applypatch/applypatch.c
+++ b/applypatch/applypatch.c
@@ -324,7 +324,7 @@
 // Save the contents of the given FileContents object under the given
 // filename.  Return 0 on success.
 int SaveFileContents(const char* filename, const FileContents* file) {
-    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC);
+    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
     if (fd < 0) {
         printf("failed to open \"%s\" for write: %s\n",
                filename, strerror(errno));
@@ -843,7 +843,7 @@
             strcpy(outname, target_filename);
             strcat(outname, ".patch");
 
-            output = open(outname, O_WRONLY | O_CREAT | O_TRUNC);
+            output = open(outname, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
             if (output < 0) {
                 printf("failed to open output file %s: %s\n",
                        outname, strerror(errno));