[safe_mode] Remove unnecessary blocking sync from successful boot reset

esphome/components/safe_mode/safe_mode.cpp

@@ -142,8 +142,10 @@ uint32_t SafeModeComponent::read_rtc_() {
 }
 
 void SafeModeComponent::clean_rtc() {
-  // Save without sync - preferences will be written at shutdown or by IntervalSyncer
-  // This avoids blocking the loop for 50+ ms on flash write
+  // Save without sync - preferences will be written at shutdown or by IntervalSyncer.
+  // This avoids blocking the loop for 50+ ms on flash write. If the device crashes
+  // before sync, the boot wasn't really successful anyway and the counter should
+  // remain incremented.
   uint32_t val = 0;
   this->rtc_.save(&val);
 }