selftests/bpf: Migrate prog_tests/trace_printk CHECKs to ASSERTs

Guidance for new tests is to use ASSERT macros instead of CHECK. Since
trace_vprintk test will borrow heavily from trace_printk's, migrate its
CHECKs so it remains obvious that the two are closely related.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-8-davemarchevsky@fb.com

tools/testing/selftests/bpf/prog_tests/trace_printk.c

@@ -10,33 +10,32 @@
 
 void test_trace_printk(void)
 {
-	int err, iter = 0, duration = 0, found = 0;
+	int err = 0, iter = 0, found = 0;
 	struct trace_printk__bss *bss;
 	struct trace_printk *skel;
 	char *buf = NULL;
 	FILE *fp = NULL;
 	size_t buflen;
 
 	skel = trace_printk__open();
-	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+	if (!ASSERT_OK_PTR(skel, "trace_printk__open"))
 		return;
 
-	ASSERT_EQ(skel->rodata->fmt[0], 'T', "invalid printk fmt string");
+	ASSERT_EQ(skel->rodata->fmt[0], 'T', "skel->rodata->fmt[0]");
 	skel->rodata->fmt[0] = 't';
 
 	err = trace_printk__load(skel);
-	if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
+	if (!ASSERT_OK(err, "trace_printk__load"))
 		goto cleanup;
 
 	bss = skel->bss;
 
 	err = trace_printk__attach(skel);
-	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+	if (!ASSERT_OK(err, "trace_printk__attach"))
 		goto cleanup;
 
 	fp = fopen(TRACEBUF, "r");
-	if (CHECK(fp == NULL, "could not open trace buffer",
-		  "error %d opening %s", errno, TRACEBUF))
+	if (!ASSERT_OK_PTR(fp, "fopen(TRACEBUF)"))
 		goto cleanup;
 
 	/* We do not want to wait forever if this test fails... */
@@ -46,14 +45,10 @@ void test_trace_printk(void)
 	usleep(1);
 	trace_printk__detach(skel);
 
-	if (CHECK(bss->trace_printk_ran == 0,
-		  "bpf_trace_printk never ran",
-		  "ran == %d", bss->trace_printk_ran))
+	if (!ASSERT_GT(bss->trace_printk_ran, 0, "bss->trace_printk_ran"))
 		goto cleanup;
 
-	if (CHECK(bss->trace_printk_ret <= 0,
-		  "bpf_trace_printk returned <= 0 value",
-		  "got %d", bss->trace_printk_ret))
+	if (!ASSERT_GT(bss->trace_printk_ret, 0, "bss->trace_printk_ret"))
 		goto cleanup;
 
 	/* verify our search string is in the trace buffer */
@@ -66,8 +61,7 @@ void test_trace_printk(void)
 			break;
 	}
 
-	if (CHECK(!found, "message from bpf_trace_printk not found",
-		  "no instance of %s in %s", SEARCHMSG, TRACEBUF))
+	if (!ASSERT_EQ(found, bss->trace_printk_ran, "found"))
 		goto cleanup;
 
 cleanup: