dumb HTTP: Clarify AsIsFilter by introducing req and res locals

No functional change.

Change-Id: I945ba18879c360f433e026aa125ef3f9f6a75793
Signed-off-by: Jonathan Nieder <jrn@google.com>

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/AsIsFileFilter.java

@@ -80,14 +80,16 @@ class AsIsFileFilter implements Filter {
 
 	public void doFilter(ServletRequest request, ServletResponse response,
 			FilterChain chain) throws IOException, ServletException {
+		HttpServletRequest req = (HttpServletRequest) request;
+		HttpServletResponse res = (HttpServletResponse) response;
 		try {
 			final Repository db = getRepository(request);
-			asIs.access((HttpServletRequest) request, db);
+			asIs.access(req, db);
 			chain.doFilter(request, response);
 		} catch (ServiceNotAuthorizedException e) {
-			((HttpServletResponse) response).sendError(SC_UNAUTHORIZED);
+			res.sendError(SC_UNAUTHORIZED);
 		} catch (ServiceNotEnabledException e) {
-			((HttpServletResponse) response).sendError(SC_FORBIDDEN);
+			res.sendError(SC_FORBIDDEN);
 		}
 	}
 }