cpupower: bench: parse.c: fix several resource leaks

The error handling in prepare_output has several issues with
resource leaks.  Ensure that filename is free'd and the directory
stream DIR is closed before returning.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NThomas Renninger <trenn@suse.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

tools/power/cpupower/bench/parse.c

@@ -81,14 +81,18 @@ FILE *prepare_output(const char *dirname)
 
 	len = strlen(dirname) + 30;
 	filename = malloc(sizeof(char) * len);
+	if (!filename) {
+		perror("malloc");
+		goto out_dir;
+	}
 
 	if (uname(&sysdata) == 0) {
 		len += strlen(sysdata.nodename) + strlen(sysdata.release);
 		filename = realloc(filename, sizeof(char) * len);
 
-		if (filename == NULL) {
+		if (!filename) {
 			perror("realloc");
-			return NULL;
+			goto out_dir;
 		}
 
 		snprintf(filename, len - 1, "%s/benchmark_%s_%s_%li.log",
@@ -104,12 +108,16 @@ FILE *prepare_output(const char *dirname)
 	if (output == NULL) {
 		perror("fopen");
 		fprintf(stderr, "error: unable to open logfile\n");
+		goto out;
 	}
 
 	fprintf(stdout, "Logfile: %s\n", filename);
 
-	free(filename);
 	fprintf(output, "#round load sleep performance powersave percentage\n");
+out:
+	free(filename);
+out_dir:
+	closedir(dir);
 	return output;
 }