Simplify vaccination_record_location

Now that either the `location_id` or the `location_name` is set on
vaccination records we can simplify this method to check either one or
the other and get the same result as we do currently.

Author: thomasleese

app/helpers/vaccination_records_helper.rb

@@ -2,17 +2,8 @@
 
 module VaccinationRecordsHelper
   def vaccination_record_location(vaccination_record)
-    if (location = vaccination_record.location)
-      if location.generic_clinic?
-        vaccination_record.location_name
-      elsif vaccination_record.already_had?
-        "Unknown"
-      else
-        location.name
-      end
-    else
-      vaccination_record.location_name
-    end
+    vaccination_record.location_name.presence ||
+      vaccination_record.location&.name || "Unknown"
   end
 
   def vaccination_record_status_tag(vaccination_record)