[ghex] meson: enable -Wformat=2

[Logan Rathbone <larathbone src gnome org>]

commit 609479a4f5fce2efbbee8d9fa14045dda97afd6b
Author: Logan Rathbone <poprocks gmail com>
Date:   Mon Jan 10 16:43:59 2022 -0500

    meson: enable -Wformat=2

 meson.build | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 2e2a4b7..3ed33ec 100644
--- a/meson.build
+++ b/meson.build
@@ -47,7 +47,8 @@ ghex_po_dir = join_paths(meson.source_root(), 'po')
 warning_cflags = [
   '-Wno-unused-variable',
   '-Wno-unused-parameter',
-  '-Werror=implicit'
+  '-Werror=implicit',
+  '-Wformat=2',
 ]
 c_compiler = meson.get_compiler('c')
 supported_warning_cflags = c_compiler.get_supported_arguments(warning_cflags)