test: Use ut_asserteq_mem() where possible

Quite a few tests still use ut_assertok(memcmp(...)) and variants. Modify
them to use the macro designed for this purpose.

Suggested-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
diff --git a/test/dm/dma.c b/test/dm/dma.c
index 12cba57..317ed4f 100644
--- a/test/dm/dma.c
+++ b/test/dm/dma.c
@@ -30,8 +30,8 @@
 		src_buf[i] = i;
 
 	ut_assertok(dma_memcpy(dst_buf, src_buf, len));
+	ut_asserteq_mem(src_buf, dst_buf, len);
 
-	ut_assertok(memcmp(src_buf, dst_buf, len));
 	return 0;
 }
 DM_TEST(dm_test_dma_m2m, DM_TESTF_SCAN_FDT);
@@ -72,7 +72,7 @@
 
 	ut_assertok(dma_free(&dma_tx));
 	ut_assertok(dma_free(&dma_rx));
-	ut_assertok(memcmp(src_buf, dst_buf, len));
+	ut_asserteq_mem(src_buf, dst_buf, len);
 
 	return 0;
 }
@@ -117,7 +117,7 @@
 
 	ut_assertok(dma_free(&dma_tx));
 	ut_assertok(dma_free(&dma_rx));
-	ut_assertok(memcmp(src_buf, dst_buf, len));
+	ut_asserteq_mem(src_buf, dst_buf, len);
 
 	return 0;
 }