Fix mkostemp64 creation mode.

All flavors of mkstemp create files with mode S_IRUSR | S_IWUSR, as
per POSIX.1-2008.  Make mkostemp64 follow that too instead of creating
files with mode S_IRUSR | S_IWUSR | S_IXUSR.

Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>

libc/stdlib/mkostemp64.c

@@ -28,5 +28,5 @@ int
 mkostemp64 (char *template, int flags)
 {
   return __gen_tempname (template, __GT_BIGFILE, flags | O_LARGEFILE, 0,
-                         S_IRUSR | S_IWUSR | S_IXUSR);
+                         S_IRUSR | S_IWUSR);
 }