selftests/lkdtm: Add UBSAN config

UBSAN_BOUNDS and UBSAN_TRAP depend on UBSAN config option.
merge_config.sh script generates following warnings if parent config
doesn't have UBSAN config already enabled and UBSAN_BOUNDS/UBSAN_TRAP
config options don't get added to the parent config.

Value requested for CONFIG_UBSAN_BOUNDS not in final .config
Requested value:  CONFIG_UBSAN_BOUNDS=y
Actual value:

Value requested for CONFIG_UBSAN_TRAP not in final .config
Requested value:  CONFIG_UBSAN_TRAP=y
Actual value:

Fix this by including UBSAN config.

Fixes: c75be56 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20220121145154.1795447-2-usama.anjum@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/selftests/lkdtm/config

@@ -5,6 +5,7 @@ CONFIG_FORTIFY_SOURCE=y
 CONFIG_HARDENED_USERCOPY=y
 CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y
 CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y
+CONFIG_UBSAN=y
 CONFIG_UBSAN_BOUNDS=y
 CONFIG_UBSAN_TRAP=y
 CONFIG_STACKPROTECTOR_STRONG=y