Fix: footprint size increased by 20B

Author: danielinux

tools/test.mk

@@ -990,7 +990,7 @@ test-size-all:
 	make keysclean
 	make test-size SIGN=ED25519 LIMIT=11448 NO_ARM_ASM=1
 	make keysclean
-	make test-size SIGN=ECC256  LIMIT=17968 NO_ARM_ASM=1
+	make test-size SIGN=ECC256  LIMIT=17988 NO_ARM_ASM=1
 	make clean
 	make test-size SIGN=ECC256 NO_ASM=1 LIMIT=13512 NO_ARM_ASM=1
 	make keysclean