The mesa winsys sometimes uses unimplemented parameter requests to
check for features. Remove the error message to avoid bloating the
kernel log.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by: Brian Paul <brianp@vmware.com> Reviewed-by: Sinclair Yeh <syeh@vmware.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>