Fix hex char codes in OCaml indexer.

Author: progoramur

opengrok-indexer/src/main/jflex/analysis/ocaml/OCaml.lexh

@@ -108,7 +108,7 @@ regular_char = \' [^ \\ \' '\010' '\013'] \'
 escaped_char = \' \\ [\\ \' \" n t b r ' '] \'
 deccode_char = \' \\ {digit}{digit}{digit} \'
 octcode_char = \' \\ o {octit}{octit}{octit} \'
-hexcode_char = \' \\ x {hexit}{hexit}{hexit} \'
+hexcode_char = \' \\ x {hexit}{hexit} \'
 
 /*
  * Extension	→	%attrid | %%attrid | @attrid

opengrok-indexer/src/test/resources/analysis/ocaml/sample2_xref.html

@@ -8,7 +8,7 @@
 <a class="l" name="5" href="#5">5</a><b>let</b> <a href="/source/s?defs=_c" class="intelliWindow-symbol" data-definition-place="undefined-in-file">_c</a> = <span class="s">&apos;c&apos;</span> <b>and</b>
 <a class="l" name="6" href="#6">6</a>    <a href="/source/s?defs=_d" class="intelliWindow-symbol" data-definition-place="undefined-in-file">_d</a> = &apos;\<span class="n">78</span>&apos; <b>and</b>
 <a class="l" name="7" href="#7">7</a>    <a href="/source/s?defs=_e" class="intelliWindow-symbol" data-definition-place="undefined-in-file">_e</a> = <span class="s">&apos;\o003&apos;</span> <b>and</b>
-<a class="l" name="8" href="#8">8</a>    <a href="/source/s?defs=_f" class="intelliWindow-symbol" data-definition-place="undefined-in-file">_f</a> = &apos;\<a href="/source/s?defs=xAf%27" class="intelliWindow-symbol" data-definition-place="undefined-in-file">xAf&apos;</a>
+<a class="l" name="8" href="#8">8</a>    <a href="/source/s?defs=_f" class="intelliWindow-symbol" data-definition-place="undefined-in-file">_f</a> = <span class="s">&apos;\xAf&apos;</span>
 <a class="l" name="9" href="#9">9</a>
 <a class="hl" name="10" href="#10">10</a><span class="c">(* {|*)|}</span><span class="c"> *)</span>
 <a class="l" name="11" href="#11">11</a>