Bug 1700472 - Add braces to SetPaginatedScrolling. r=dholbert

Drive-by fixup while I was reading related code.

Depends on D109545

Differential Revision: https://phabricator.services.mozilla.com/D109546

layout/base/nsPresContext.cpp

@@ -1665,8 +1665,9 @@ nsCompatibility nsPresContext::CompatibilityMode() const {
 }
 
 void nsPresContext::SetPaginatedScrolling(bool aPaginated) {
-  if (mType == eContext_PrintPreview || mType == eContext_PageLayout)
+  if (mType == eContext_PrintPreview || mType == eContext_PageLayout) {
     mCanPaginatedScroll = aPaginated;
+  }
 }
 
 void nsPresContext::SetPrintSettings(nsIPrintSettings* aPrintSettings) {