fellow_storage: Turn a wrong INCOMPL() into a right WRONG()

src/fellow_storage.c

@@ -2614,7 +2614,7 @@ sfe_close(const struct stevedore *stv, int warn)
 		sfe_close_real(stvfe);
 		break;
 	default:
-		INCOMPL();
+		WRONG("sfe_close warn value");
 	}
 }