Continue fixing FX_BOOL / int noise

Review-Url: https://codereview.chromium.org/2459073002
diff --git a/fpdfsdk/cpdfsdk_formfillenvironment.cpp b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
index d93e309..f729f71 100644
--- a/fpdfsdk/cpdfsdk_formfillenvironment.cpp
+++ b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
@@ -766,5 +766,5 @@
 }
 
 FX_BOOL CPDFSDK_FormFillEnvironment::GetPermissions(int nFlag) {
-  return GetPDFDocument()->GetUserPermissions() & nFlag;
+  return !!(GetPDFDocument()->GetUserPermissions() & nFlag);
 }