Forgot it's a struct

lib/gtls.h

@@ -58,7 +58,7 @@ int Curl_gtls_shutdown(struct connectdata *conn, int sockindex);
 #define curlssl_shutdown(x,y) Curl_gtls_shutdown(x,y)
 #define curlssl_set_engine(x,y) (x=x, y=y, CURLE_FAILED_INIT)
 #define curlssl_set_engine_default(x) (x=x, CURLE_FAILED_INIT)
-#define curlssl_engines_list(x) (x=x, (curl_slist *)NULL)
+#define curlssl_engines_list(x) (x=x, (struct curl_slist *)NULL)
 #define curlssl_send Curl_gtls_send
 #define curlssl_recv Curl_gtls_recv
 #define curlssl_version Curl_gtls_version

lib/nssg.h

@@ -70,7 +70,7 @@ int Curl_nss_seed(struct SessionHandle *data);
 #define curlssl_shutdown(x,y) (x=x, y=y, 1)
 #define curlssl_set_engine(x,y) (x=x, y=y, CURLE_FAILED_INIT)
 #define curlssl_set_engine_default(x) (x=x, CURLE_FAILED_INIT)
-#define curlssl_engines_list(x) (x=x, (curl_slist *)NULL)
+#define curlssl_engines_list(x) (x=x, (struct curl_slist *)NULL)
 #define curlssl_send Curl_nss_send
 #define curlssl_recv Curl_nss_recv
 #define curlssl_version Curl_nss_version