lib: fix gcc8 warning on Windows

Closes https://github.com/curl/curl/pull/2979

diff --git a/lib/curl_sspi.c b/lib/curl_sspi.c
index 11a7120a9f4a748f83a2b211063d9a8a630354db..7d1934297782c2524beeec5752d576c2179f8fe6 100644 (file)
--- a/lib/curl_sspi.c
+++ b/lib/curl_sspi.c
@@ -90,8 +90,9 @@ CURLcode Curl_sspi_global_init(void)
       return CURLE_FAILED_INIT;
 
     /* Get address of the InitSecurityInterfaceA function from the SSPI dll */
-    pInitSecurityInterface = (INITSECURITYINTERFACE_FN)
-      GetProcAddress(s_hSecDll, SECURITYENTRYPOINT);
+    pInitSecurityInterface =
+      CURLX_FUNCTION_CAST(INITSECURITYINTERFACE_FN,
+                          (GetProcAddress(s_hSecDll, SECURITYENTRYPOINT)));
     if(!pInitSecurityInterface)
       return CURLE_FAILED_INIT;