smb: Use the correct error code for access denied on file open

- Return CURLE_REMOTE_ACCESS_DENIED for SMB access denied on file open.

Prior to this change CURLE_REMOTE_FILE_NOT_FOUND was returned instead.

Closes https://github.com/curl/curl/pull/4095
diff --git a/lib/smb.c b/lib/smb.c
index 5a4b780..870244c 100644
--- a/lib/smb.c
+++ b/lib/smb.c
@@ -785,6 +785,8 @@
   case SMB_OPEN:
     if(h->status || smbc->got < sizeof(struct smb_nt_create_response)) {
       req->result = CURLE_REMOTE_FILE_NOT_FOUND;
+      if(h->status == smb_swap32(SMB_ERR_NOACCESS))
+        req->result = CURLE_REMOTE_ACCESS_DENIED;
       next_state = SMB_TREE_DISCONNECT;
       break;
     }