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/axi.c b/test/dm/axi.c
index 289f07a..e1155a5 100644
--- a/test/dm/axi.c
+++ b/test/dm/axi.c
@@ -66,11 +66,11 @@
 	/* Test writing */
 	val = 0x55667788;
 	axi_write(store, 0, &val, AXI_SIZE_32);
-	ut_asserteq(0, memcmp(data, tdata1, ARRAY_SIZE(tdata1)));
+	ut_asserteq_mem(data, tdata1, ARRAY_SIZE(tdata1));
 
 	val = 0xaabbccdd;
 	axi_write(store, 3, &val, AXI_SIZE_32);
-	ut_asserteq(0, memcmp(data + 3, tdata2, ARRAY_SIZE(tdata1)));
+	ut_asserteq_mem(data + 3, tdata2, ARRAY_SIZE(tdata1));
 
 	return 0;
 }