schannel: deduplicate Windows Vista detection

curl detects Vista as part of its global initialization. Use that result
instead of detecting it again in Schannel, to save some cycles and API
calls.

Follow-up to 46e97b10ba917aed55f079b89c1dfe54955a4a62 #16400
Closes #16408

diff --git a/lib/vtls/schannel.c b/lib/vtls/schannel.c
index ffd681bd3845e015ea526c359aa5a6176d9cc279..99ce5cb0c8e09afafd826e19ef530d90186067a4 100644 (file)
--- a/lib/vtls/schannel.c
+++ b/lib/vtls/schannel.c
@@ -53,6 +53,7 @@
 #include "x509asn1.h"
 #include "curl_printf.h"
 #include "multiif.h"
+#include "system_win32.h"
 #include "version_win32.h"
 #include "rand.h"
 #include "strparse.h"
@@ -651,8 +652,7 @@ schannel_acquire_credential_handle(struct Curl_cfilter *cf,
         else
           pszPassword[0] = 0;
 
-        if(curlx_verify_windows_version(6, 0, 0, PLATFORM_WINNT,
-                                        VERSION_GREATER_THAN_EQUAL))
+        if(Curl_isVistaOrGreater)
           cert_store = PFXImportCertStore(&datablob, pszPassword,
                                           PKCS12_NO_PERSIST_KEY);
         else