x86/platform/intel/quark: Add printf attribute to imr_self_test_result()

__printf() attributes help detecting issues in printf() format strings at
compile time.

Even though imr_selftest.c is only compiled with
CONFIG_DEBUG_IMR_SELFTEST=y, GCC complains about a missing format
attribute when compiling allmodconfig with -Wmissing-format-attribute.

Silence this warning by adding the attribute.

Signed-off-by: Nicolas Iooss <[e-mail]>
Acked-by: Bryan O'Donoghue <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/platform/intel-quark/imr_selftest.c

···
  * @fmt:	format string.
  * ...		variadic argument list.
  */
-static void __init imr_self_test_result(int res, const char *fmt, ...)
+static __printf(2, 3)
+void __init imr_self_test_result(int res, const char *fmt, ...)
 {
 	va_list vlist;