TESTS: pass an actual block to the ritesame16/0blocks test

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>

test-tool/test_writesame10_0blocks.c

@@ -40,6 +40,7 @@ test_writesame10_0blocks(void)
 	logging(LOG_VERBOSE, LOG_BLANK_LINE);
 	logging(LOG_VERBOSE, "Test WRITESAME10 0-blocks at LBA==0 (WSNZ=%d)",
 		inq_bl->wsnz);
+	memset(buf, 0, block_size);
 	ret = writesame10(sd, 0,
 			  block_size, 0, 0, 0, 0, 0, buf,
 			  EXPECT_STATUS_GOOD);