Fix markup for sun-5.8

[SVN r35681]

status/explicit-failures-markup.xml

@@ -1270,7 +1270,7 @@
         <mark-expected-failures>
           <test name="mbcopy"/>
           <test name="wide_test"/>
-          <toolset name="sun-5_8"/>
+          <toolset name="sun-5.8"/>
            <note author="John Maddock">
               These failures are reported to be fixed in Sun's 
               next compiler release.
@@ -3265,7 +3265,7 @@ for more information.
           <test name="optional_deduced_sfinae"/>
           <test name="preprocessor_deduced"/>
           <test name="python_test"/>
-          <toolset name="sun-5_8"/>
+          <toolset name="sun-5.8"/>
           <note author="John Maddock">
              These test failure are reported to be under investigation
              at Sun's compiler labs.