utilfdt_read_err: use xmalloc funcs

We've got these handy helpers, so let's use them.

Acked-by: David Gibson <David@gibson.dropbear.id.au>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/util.c b/util.c
index b081fa8..12f0614 100644
--- a/util.c
+++ b/util.c
@@ -212,12 +212,12 @@
 	}
 
 	/* Loop until we have read everything */
-	buf = malloc(bufsize);
+	buf = xmalloc(bufsize);
 	do {
 		/* Expand the buffer to hold the next chunk */
 		if (offset == bufsize) {
 			bufsize *= 2;
-			buf = realloc(buf, bufsize);
+			buf = xrealloc(buf, bufsize);
 			if (!buf) {
 				ret = ENOMEM;
 				break;