Use app_malloc; two missing cases.

Reviewed-by: NMatt Caswell <matt@openssl.org>

apps/apps.c

@@ -2633,7 +2633,7 @@ void wait_for_async(SSL *s)
         return;
     if (numfds == 0)
         return;
-    fds = OPENSSL_malloc(sizeof(OSSL_ASYNC_FD) * numfds);
+    fds = app_malloc(sizeof(OSSL_ASYNC_FD) * numfds, "allocate async fds");
     if (!SSL_get_all_async_fds(s, fds, &numfds)) {
         OPENSSL_free(fds);
     }

apps/s_client.c

@@ -509,7 +509,7 @@ static ossl_ssize_t hexdecode(const char **inptr, void *result)
 {
     unsigned char **out = (unsigned char **)result;
     const char *in = *inptr;
-    unsigned char *ret = OPENSSL_malloc(strlen(in)/2);
+    unsigned char *ret = app_malloc(strlen(in)/2, "hexdecode");
     unsigned char *cp = ret;
     uint8_t byte;
     int nibble = 0;