selftests: move openat2 tests to selftests/filesystems/

These tests really should've always belonged there, doubly so now that
they include a lot of other generic filesystem-related tests.

Suggested-by: Christian Brauner <[email protected]>
Signed-off-by: Aleksa Sarai <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Christian Brauner (Amutable) <[email protected]>

tools/testing/selftests/filesystems/openat2/Makefile

@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+CFLAGS += $(KHDR_INCLUDES)
 CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined
 TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test
 
@@ -13,6 +14,6 @@ endif
 
 LOCAL_HDRS += helpers.h
 
-include ../lib.mk
+include ../../lib.mk
 
 $(TEST_GEN_PROGS): helpers.c