Remove unnecessary null pointer checks.  We want the caller of
these functions to do their own pointer checks.  Add some
comments to document this.
Signed-off-by: NAlan Tull <atull@opensource.altera.com>
Reviewed-by: NMoritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>