Repair glibc make check with -Wformat options enabled.

Repair glibc make check with -Wformat options enabled.

With -Wformat options enabled there are test fails:

  cc1: error: -Wformat-security ignored without -Wformat [-Werror=format-security]
  cc1: all warnings being treated as errors
  ../o-iterator.mk:9: recipe for target
  '/home/abuild/rpmbuild/BUILD/glibc-2.24/cc-base/time/test_time.o' failed

As some targets disables -Wformat explicitly:

(time/Makefile):
  # Don't warn about Y2k problem in strftime format string.
  CFLAGS-test_time.c = -Wno-format

Change-Id: Ic0f8b6bb07ea7875a75b994584ac10cec6515827