[PATCH 2/2] grub2: fix build with gcc-7

[Martin Jansa <martin.jansa@gmail.com>]

* build with gcc-7 fails with:
  | ./config-util.h:1504:48: error: this use of "defined" may not be   portable [-Werror=expansion-to-defined]
  |              || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
  |                                                 ^~~~~~~~~~~~~~~
  and we're not building on Apple or BSD, so we should be able
  to just ignoreit until it's resolved properly in some newer gnulib
  and imported from gnulib to grub-2

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
---
 meta/recipes-bsp/grub/grub-efi_2.02.bb | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meta/recipes-bsp/grub/grub-efi_2.02.bb b/meta/recipes-bsp/grub/grub-efi_2.02.bb
index b949bebced..45f4c1ed34 100644
--- a/meta/recipes-bsp/grub/grub-efi_2.02.bb
+++ b/meta/recipes-bsp/grub/grub-efi_2.02.bb
@@ -36,6 +36,12 @@ EXTRA_OECONF += "--enable-efiemu=no"
 # and many other places in the grub code when compiled with some native gcc compilers (specifically, gentoo)
 CFLAGS_append_class-native = " -Wno-error=trampolines"
 
+# this comes from gnulib and it's used only for Apple and BSD, so we can ignore it
+# ./config-util.h:1504:48: error: this use of "defined" may not be portable [-Werror=expansion-to-defined]
+#             || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
+#                                                ^~~~~~~~~~~~~~~
+CFLAGS_append_class-native = " -Wno-error=expansion-to-defined"
+
 do_install_class-native() {
 	install -d ${D}${bindir}
 	install -m 755 grub-mkimage ${D}${bindir}
-- 
2.14.1