Fix setenv(), remove comment.

src/sbbs3/xtrn.cpp

@@ -1080,8 +1080,8 @@ static int setenv(const char *name, const char *value, int overwrite)
 			errno=ENOMEM;
 			return(-1);
 		}
-		/* ToDo: (comment for shurd) */
-		/* Uh... I'm pretty sure we're missing an sprintf() call here or something... */
+		/* Note, on some platforms, this can be free()d... */
+		sprintf(envstr,"%s=%s",name,value);
 		putenv(envstr);
 	}
 	return(0);