6879368: Remove stray quote in Character javadoc

Summary: Remove stray quote in Character.valueOf javadoc, using Ulf's \u005CuXXXX technique
Reviewed-by: darcy

src/share/classes/java/lang/Character.java

@@ -2587,9 +2587,9 @@ class Character extends Object implements java.io.Serializable, Comparable<Chara
      * significantly better space and time performance by caching
      * frequently requested values.
      *
-     * This method will always cache values in the range '&#92;u0000'
-     * to '&#92;u007f'", inclusive, and may cache other values outside
-     * of this range.
+     * This method will always cache values in the range {@code
+     * '\u005Cu0000'} to {@code '\u005Cu007f'}, inclusive, and may
+     * cache other values outside of this range.
      *
      * @param  c a char value.
      * @return a <tt>Character</tt> instance representing <tt>c</tt>.