[PAL] Clean up reference monitor residues

Pal/Makefile

@@ -18,8 +18,6 @@ format:
 	clang-format -i $(shell find . -path ./lib/crypto/mbedtls -prune -o \
 	                               -path ./lib/crypto/udivmodti4.c -prune -o \
 	                               -path ./src/host/Linux-SGX/sgx-driver -prune -o \
-	                               -path ./src/security/Linux/bpf-helper.h -prune -o \
-	                               -path ./src/security/Linux/bpf_helper.c -prune -o \
 	                               \( -name '*.h' -o -name '*.c' \) -print)
 
 .PHONY: pack

Pal/src/Makefile

@@ -146,4 +146,3 @@ $(OBJ_DIR)/%.s: %.c $(headers)
 clean:
 	rm -rf $(LIB_DIR) $(OBJ_DIR) $(files_to_build)
 	@[ ! -d $(HOST_DIR) ] || $(MAKE) -C $(HOST_DIR) clean
-	@[ ! -d security/$(PAL_HOST) ] || $(MAKE) -C security/$(PAL_HOST) clean