staging: uwb: fix coccinelle warnings of comparison to bool

Fix warnings of comparision to bool.
Issue detected by coccinelle tool.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Link: https://lore.kernel.org/r/20191022185328.9387-1-jbi.octave@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>