Fix crypto submodule usage in Makefile
diff --git a/Makefile b/Makefile
index 2db2644..c83c64e 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@
tests: lib
$(MAKE) -C tests
-ifdef USE_CRYPTO_SUBMODULE
+ifneq ($(USE_CRYPTO_SUBMODULE), 0)
$(MAKE) CRYPTO_INCLUDES:="-I../../include -I../include" -C crypto/tests
endif
@@ -109,7 +109,7 @@
check: lib tests
$(MAKE) -C tests check
-ifdef USE_CRYPTO_SUBMODULE
+ifneq ($(USE_CRYPTO_SUBMODULE), 0)
$(MAKE) CRYPTO_INCLUDES:="-I../../include -I../include" -C crypto/tests check
endif