mdadm: Fix memory leak issue in load_ddf_local()

dl->devname might be allocated space through xstrdup(). Before an
abnormal exit, it needs to be checked and released.

Signed-off-by: Wu Guanghao <[email protected]>

Author: wuguanghao3

super-ddf.c

@@ -1208,6 +1208,8 @@ static int load_ddf_local(int fd, struct ddf_super *super,
 	dl->devname = devname ? xstrdup(devname) : NULL;
 
 	if (fstat(fd, &stb) != 0) {
+		if (dl->devname)
+			free(dl->devname);
 		free(dl);
 		return 1;
 	}