PSR2/SwitchDeclaration: update doc as case indentation is not checked

The sniff no longer checks `case` keyword indentation as of commit
4a39005, but the corresponding XML documentation was not updated. This
commit aligns the documentation with the current sniff behavior by
removing mentions of `case` indentation checks.

Author: rodrigoprimo

src/Standards/PSR2/Docs/ControlStructures/SwitchDeclarationStandard.xml

@@ -1,27 +1,9 @@
 <documentation title="Switch Declarations">
     <standard>
     <![CDATA[
-    Case statements should be indented 4 spaces from the switch keyword.  It should also be followed by a space.  Colons in switch declarations should not be preceded by whitespace.  Break statements should be indented 4 more spaces from the case statement.  There must be a comment when falling through from one case into the next.
+    Case statements should be followed by a space.  Colons in switch declarations should not be preceded by whitespace.  Break statements should be indented 4 more spaces from the case statement.  There must be a comment when falling through from one case into the next.
     ]]>
     </standard>
-    <code_comparison>
-        <code title="Valid: Case statement indented correctly.">
-        <![CDATA[
-switch ($foo) {
-<em>    </em>case 'bar':
-        break;
-}
-        ]]>
-        </code>
-        <code title="Invalid: Case statement not indented 4 spaces.">
-        <![CDATA[
-switch ($foo) {
-<em></em>case 'bar':
-    break;
-}
-        ]]>
-        </code>
-    </code_comparison>
     <code_comparison>
         <code title="Valid: Case statement followed by 1 space.">
         <![CDATA[