Close HTML tag in artifactChecksums.exsd

Change-Id: I77151f11c944c5642b7a2e5cb0e5f898628dab08
Signed-off-by: Mykola Nikishov <mn@mn.com.ua>
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/schema/artifactChecksums.exsd b/bundles/org.eclipse.equinox.p2.artifact.repository/schema/artifactChecksums.exsd
index daf3ff5..edfe4a2 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/schema/artifactChecksums.exsd
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/schema/artifactChecksums.exsd
@@ -118,7 +118,7 @@
          <meta.section type="implementation"/>
       </appInfo>
       <documentation>
-         Contributes a checksum algorithm with id &lt;code&gt;sha-256&lt;code&gt; and maps it to &lt;code&gt;SHA-256&lt;/code&gt; MessageDigest implementation.
+         Contributes a checksum algorithm with id &lt;code&gt;sha-256&lt;/code&gt; and maps it to &lt;code&gt;SHA-256&lt;/code&gt; MessageDigest implementation.
       </documentation>
    </annotation>