docs: fix incorrectly closed paragraph

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>

docs/meson.html

@@ -239,6 +239,7 @@ As of meson 0.49.0 meson also has the concept of a
 these files provide information about the native build environment (as opposed
 to a cross build environment). They are ini formatted and can override where to
 find llvm-config:
+</p>
 
 custom-llvm.ini
 <pre>
@@ -251,7 +252,7 @@ Then configure meson:
 <pre>
     meson builddir/ --native-file custom-llvm.ini
 </pre>
-</p></dd>
+</dd>
 
 <dd><p>
 For selecting llvm-config for cross compiling a