Avoid stack overflow in alltypes_proto3 testcase on AVR
diff --git a/tests/alltypes_proto3/decode_alltypes.c b/tests/alltypes_proto3/decode_alltypes.c
index 114e78b..2e45b7d 100644
--- a/tests/alltypes_proto3/decode_alltypes.c
+++ b/tests/alltypes_proto3/decode_alltypes.c
@@ -9,16 +9,13 @@
 #include <pb_decode.h>
 #include "alltypes.pb.h"
 #include "test_helpers.h"
-
-#define TEST(x) if (!(x)) { \
-    printf("Test " #x " failed.\n"); \
-    return false; \
-    }
+#include "unittests.h"
 
 /* This function is called once from main(), it handles
    the decoding and checks the fields. */
 bool check_alltypes(pb_istream_t *stream, int mode)
 {
+    int status = 0;
     AllTypes alltypes = AllTypes_init_zero;
 
     /* Fill with garbage to better detect initialization errors */
@@ -139,7 +136,7 @@
 
     TEST(alltypes.end == 1099);
 
-    return true;
+    return status == 0;
 }
 
 int main(int argc, char **argv)