kunit: test: fix incorrect KUnit log prefix

00ab351275786418b766fca296b61217bf59447c (kunit: test: port test abort
support to x86) incorrectly changed the KUnit log prefix from "kunit" to
"test" which made the kunit_tool unable to parse the raw logs. This
fixes that.

Google-Bug-Id: 135477354
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Change-Id: I0d0c4e10d2672b1bfa2434153e9253df171a5041
diff --git a/test/test.c b/test/test.c
index 1e99413..baece69 100644
--- a/test/test.c
+++ b/test/test.c
@@ -85,7 +85,7 @@
 {
 	test_printk_emit(test,
 			 level[1] - '0',
-			 "test %s: %pV", test->name, vaf);
+			 "kunit %s: %pV", test->name, vaf);
 }
 
 static void test_fail(struct test *test, struct test_stream *stream)