fix MinGW format attribute

Setting -D__USE_MINGW_ANSI_STDIO=1 is wrong and should not be used. MinGW
internally uses a macro to select between gnu_printf and printf. Just use
that instead of using a wrong format under clang backends.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

meson.build

@@ -22,13 +22,6 @@ add_project_arguments(
   language: 'c'
 )
 
-if host_machine.system() == 'windows'
-  add_project_arguments(
-    '-D__USE_MINGW_ANSI_STDIO=1',
-    language: 'c'
-  )
-endif
-
 add_project_arguments(
   '-DFDT_ASSUME_MASK=' + get_option('assume-mask').to_string(),
   language: 'c'

util.h

@@ -13,7 +13,9 @@
  */
 
 #ifdef __GNUC__
-#if __GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
+#ifdef __MINGW_PRINTF_FORMAT
+#define PRINTF(i, j)	__attribute__((format (__MINGW_PRINTF_FORMAT, i, j)))
+#elif __GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
 #define PRINTF(i, j)	__attribute__((format (gnu_printf, i, j)))
 #else
 #define PRINTF(i, j)	__attribute__((format (printf, i, j)))