[PATCH] Makefile: 'Promote' -Wunused-but-set-variable to W=3

[Peter Zijlstra]

Upgrade -Wunused-but-set-variable to W=3 to avoid the build robots
sending endless spam for this garbage warning.

By promoting it to W=3 the robots will no longer report it and people
will no longer attempt to fix them by making the code worse.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index d53825503874..6686cc587d3b 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -28,7 +28,6 @@ KBUILD_CFLAGS += -Wmissing-format-attribute
 KBUILD_CFLAGS += -Wmissing-prototypes
 KBUILD_CFLAGS += -Wold-style-definition
 KBUILD_CFLAGS += -Wmissing-include-dirs
-KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable)
 KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
 KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned)
 KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation)
@@ -88,6 +87,7 @@ KBUILD_CFLAGS += -Wredundant-decls
 KBUILD_CFLAGS += -Wsign-compare
 KBUILD_CFLAGS += -Wswitch-default
 KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
+KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable)
 
 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3