ams: use R_SUCCEED, R_THROW globally

libraries/libstratosphere/source/fssystem/fssystem_key_slot_cache.hpp

@@ -93,12 +93,12 @@ namespace ams::fssystem {
                             *out = std::move(accessor);
 
                             this->UpdateMru(list, it);
-                            return ResultSuccess();
+                            R_SUCCEED();
                         }
                     }
                 }
 
-                return fs::ResultTargetNotFound();
+                R_THROW(fs::ResultTargetNotFound());
             }
 
             void AddEntry(KeySlotCacheEntry *entry) {
@@ -122,7 +122,7 @@ namespace ams::fssystem {
                 src_list.pop_back();
                 dst_list.push_front(*entry);
 
-                return ResultSuccess();
+                R_SUCCEED();
             }
 
             void UpdateMru(KeySlotCacheEntryList *list, KeySlotCacheEntryList::iterator it) {