Revert "tests: logging: log_api: Add cast to char array"

This reverts commit 265394e.

The underlying cause is fixed so reverting this...

Signed-off-by: Daniel Leung <[email protected]>

Author: dcpleung

tests/subsys/logging/log_api/src/main.c

@@ -218,7 +218,7 @@ ZTEST(test_log_api, test_log_various_messages)
 				CONFIG_LOG_DOMAIN_ID, LOG_LEVEL_ERR,
 				exp_timestamp++, "err");
 
-	LOG_WRN("wrn %s", (char *)dstr);
+	LOG_WRN("wrn %s", dstr);
 	dstr[0] = '\0';
 
 	LOG_ERR("err");