DocBook/drm: Clean up `pre-memory management aware'

Signed-off-by: Michael Witten <mfwitten@gmail.com>

Documentation/DocBook/drm.tmpl

@@ -273,7 +273,7 @@
       conflict with DRM client requirements.  For instance, if user
       level mode setting drivers are in use, it would be problematic
       to perform output discovery & configuration at load time.
-      Likewise, if pre-memory management aware user level drivers are
+      Likewise, if user-level drivers unaware of memory management are
       in use, memory management and command buffer setup may need to
       be omitted.  These requirements are driver specific, and care
       needs to be taken to keep both old and new applications and