Make crypto_{kem,sign} part of SCHEME variable

Makefile

@@ -1,5 +1,5 @@
 
-# assumes a SCHEME variable; e.g. make functest_kem SCHEME=kyber768
+# assumes a SCHEME variable; e.g. make functest_kem SCHEME=crypto_kem/kyber768
 ifndef SCHEME
 	# TODO make this more granular, i.e. make clean should not require SCHEME
 $(error SCHEME variable is not set)
@@ -7,14 +7,14 @@ endif
 
 CFLAGS=-Wall -Wextra -Wpedantic -Werror -std=c99
 
-functest_kem: crypto_kem/test.c $(wildcard crypto_kem/$(SCHEME)/clean/*.c) $(wildcard crypto_kem/$(SCHEME)/clean/*.h)
+functest_kem: crypto_kem/test.c $(wildcard $(SCHEME)/clean/*.c) $(wildcard $(SCHEME)/clean/*.h)
 	mkdir -p bin
 	$(CC) $(CFLAGS)\
 		-I"./common/"\
-		-I"crypto_kem/$(SCHEME)/clean/"\
+		-I"$(SCHEME)/clean/"\
 		-o bin/functest_kem_$(SCHEME)\
 		common/*.c\
-		crypto_kem/$(SCHEME)/clean/*.c\
+		$(SCHEME)/clean/*.c\
 		crypto_kem/test.c
 
 .PHONY: clean