Move ability check to its own method

app/finders/sentry_issues_finder.rb

@@ -7,7 +7,7 @@ class SentryIssuesFinder
   end
 
   def find_by_identifier(identifier)
-    return unless Ability.allowed?(@current_user, :read_sentry_issue, @project)
+    return unless authorized?
 
     sentry_issue = SentryIssue.for_identifier(identifier).first
 
@@ -15,4 +15,10 @@ class SentryIssuesFinder
 
     sentry_issue
   end
+
+  private
+
+  def authorized?
+    Ability.allowed?(@current_user, :read_sentry_issue, @project)
+  end
 end