selftest: sync: improve assert() failure message

Print "ERROR" on all messages instead of using the not well defined terms
like "BAD".

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/sync/synctest.h

@@ -32,7 +32,7 @@
 
 #define ASSERT(cond, msg) do { \
 	if (!(cond)) { \
-		printf("[BAD]\t%s", (msg)); \
+		printf("[ERROR]\t%s", (msg)); \
 		return 1; \
 	} \
 } while (0)