kstack_erase: Fix missed export of renamed KSTACK_ERASE_CFLAGS

Certain targets disable kstack_erase by filtering out KSTACK_ERASE_CFLAGS
rather than adding DISABLE_KSTACK_ERASE. The renaming to kstack_erase
missed the CFLAGS export, which broke those build targets (e.g. x86
vdso32).

Fixes: 76261fc ("stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS")
Signed-off-by: Kees Cook <[email protected]>

Author: kees

scripts/Makefile.kstack_erase

@@ -16,6 +16,6 @@ endif
 
 KSTACK_ERASE_CFLAGS   := $(kstack-erase-cflags-y)
 
-export STACKLEAK_CFLAGS DISABLE_KSTACK_ERASE
+export KSTACK_ERASE_CFLAGS DISABLE_KSTACK_ERASE
 
 KBUILD_CFLAGS += $(KSTACK_ERASE_CFLAGS)