[PATCH] uml: fix big stack user

Switch this proc from storing 4k of data (a whole path) on the stack to
keeping it on the heap.

Maybe it's not called in process context but only in early boot context (where
in UML you have a normal process stack on the host) but just to be safe, fix
it.

While at it some little readability simplifications.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/os-Linux/mem.c

@@ -53,33 +53,36 @@ static void __init find_tempdir(void)
  */
 int make_tempfile(const char *template, char **out_tempname, int do_unlink)
 {
-	char tempname[MAXPATHLEN];
+	char *tempname;
 	int fd;
 
+	tempname = malloc(MAXPATHLEN);
+
 	find_tempdir();
-	if (*template != '/')
+	if (template[0] != '/')
 		strcpy(tempname, tempdir);
 	else
-		*tempname = 0;
+		tempname[0] = '\0';
 	strcat(tempname, template);
 	fd = mkstemp(tempname);
 	if(fd < 0){
 		fprintf(stderr, "open - cannot create %s: %s\n", tempname,
 			strerror(errno));
-		return -1;
+		goto out;
 	}
 	if(do_unlink && (unlink(tempname) < 0)){
 		perror("unlink");
-		return -1;
+		goto out;
 	}
 	if(out_tempname){
-		*out_tempname = strdup(tempname);
-		if(*out_tempname == NULL){
-			perror("strdup");
-			return -1;
-		}
+		*out_tempname = tempname;
+	} else {
+		free(tempname);
 	}
 	return(fd);
+out:
+	free(tempname);
+	return -1;
 }
 
 #define TEMPNAME_TEMPLATE "vm_file-XXXXXX"