fix preload never being restricted (#3012)

Fix preload never being restricted

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt

@@ -132,16 +132,16 @@ abstract class PagerViewer(val activity: ReaderActivity) : BaseViewer {
 
     private fun checkAllowPreload(page: ReaderPage?): Boolean {
         // Page is transition page - preload allowed
-        page == null ?: return true
+        page ?: return true
 
         // Initial opening - preload allowed
-        currentPage == null ?: return true
+        currentPage ?: return true
 
         // Allow preload for
         // 1. Going to next chapter from chapter transition
         // 2. Going between pages of same chapter
         // 3. Next chapter page
-        return when (page!!.chapter) {
+        return when (page.chapter) {
             (currentPage as? ChapterTransition.Next)?.to -> true
             (currentPage as? ReaderPage)?.chapter -> true
             adapter.nextTransition?.to -> true

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonViewer.kt

@@ -125,10 +125,10 @@ class WebtoonViewer(val activity: ReaderActivity, val isContinuous: Boolean = tr
 
     private fun checkAllowPreload(page: ReaderPage?): Boolean {
         // Page is transition page - preload allowed
-        page == null ?: return true
+        page ?: return true
 
         // Initial opening - preload allowed
-        currentPage == null ?: return true
+        currentPage ?: return true
 
         val nextItem = adapter.items.getOrNull(adapter.items.count() - 1)
         val nextChapter = (nextItem as? ChapterTransition.Next)?.to ?: (nextItem as? ReaderPage)?.chapter
@@ -136,7 +136,7 @@ class WebtoonViewer(val activity: ReaderActivity, val isContinuous: Boolean = tr
         // Allow preload for
         // 1. Going between pages of same chapter
         // 2. Next chapter page
-        return when (page!!.chapter) {
+        return when (page.chapter) {
             (currentPage as? ReaderPage)?.chapter -> true
             nextChapter -> true
             else -> false