change interface to bb_xasprintf() - more perfect for me.

ln.c: error_msg(str)->error_msg(%s, str) - remove standart "feature" for hackers
reduce 100 bytes don't care in sum

e2fsprogs/mke2fs.c

@@ -794,10 +794,7 @@ static int PRS(int argc, char *argv[])
 
 	/* Update our PATH to include /sbin  */
 	if (oldpath) {
-		char *newpath;
-
-		bb_xasprintf(&newpath, "%s:%s", PATH_SET, oldpath);
-		putenv(newpath);
+		putenv (bb_xasprintf("%s:%s", PATH_SET, oldpath));
 	} else
 		putenv (PATH_SET);