If mountnfs returns an error, it will have already freed nam; no need to

free it again.

Reported by:	"Ted Unangst" <tedu@coverity.com>
Approved by:	rwatson (mentor)

sys/nfsclient/nfs_vfsops.c

@@ -507,7 +507,6 @@ nfs_mountdiskless(char *path, char *which, int mountflag,
 	if ((error = mountnfs(args, mp, nam, which, path, vpp,
 	    td->td_ucred)) != 0) {
 		printf("nfs_mountroot: mount %s on %s: %d", path, which, error);
-		FREE(nam, M_SONAME);
 		return (error);
 	}
 	(void) copystr(which, mp->mnt_stat.f_mntonname, MNAMELEN - 1, 0);