selftests: kvm: Introduce the TEST_FAIL macro

Some tests/utilities use the TEST_ASSERT(false, ...) pattern to
indicate a failure and stop execution.

This change introduces the TEST_FAIL macro which is a wrap around
TEST_ASSERT(false, ...) and so provides a direct alternative for
failing a test.

Signed-off-by: Wainer dos Santos Moschetta <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

tools/testing/selftests/kvm/include/test_util.h

···
 		    #a, #b, #a, (unsigned long) __a, #b, (unsigned long) __b); \
 } while (0)
 
+#define TEST_FAIL(fmt, ...) \
+	TEST_ASSERT(false, fmt, ##__VA_ARGS__)
+
 size_t parse_size(const char *size);
 
 int64_t timespec_to_ns(struct timespec ts);