simplify

src/main/java/org/cobbzilla/util/io/FilenameSuffixFilter.java

@@ -2,7 +2,6 @@ package org.cobbzilla.util.io;
 
 import lombok.AllArgsConstructor;
 import lombok.Getter;
-import lombok.Setter;
 
 import java.io.File;
 import java.io.FilenameFilter;
@@ -10,10 +9,8 @@ import java.io.FilenameFilter;
 @AllArgsConstructor
 public class FilenameSuffixFilter implements FilenameFilter {
 
-    @Getter @Setter private String suffix;
+    @Getter private final String suffix;
 
-    @Override public boolean accept(File dir, String name) {
-        return name.endsWith(suffix);
-    }
+    @Override public boolean accept(File dir, String name) { return name.endsWith(suffix); }
 
 }