Revert "Cumulative patch from commit 4ec1fd8e42bad9390f14a58225b6e5f6fb691950"

This reverts commit 78a5dac804c22aa6e4ec8226a864d3b0d6ccddbb.

Test: None
diff --git a/src/utils/wpabuf.c b/src/utils/wpabuf.c
index 77ee472..96cb25c 100644
--- a/src/utils/wpabuf.c
+++ b/src/utils/wpabuf.c
@@ -244,13 +244,15 @@
 
 	if (a)
 		len += wpabuf_len(a);
-	len += wpabuf_len(b);
+	if (b)
+		len += wpabuf_len(b);
 
 	n = wpabuf_alloc(len);
 	if (n) {
 		if (a)
 			wpabuf_put_buf(n, a);
-		wpabuf_put_buf(n, b);
+		if (b)
+			wpabuf_put_buf(n, b);
 	}
 
 	wpabuf_free(a);