ray_cs: remove redundant pointer 'p'

Pointer 'p' is being assigned but is never used hence it is
redundant and can be removed. Also re-work if statement to remove
redundant assignment of p.

Cleans up clang warning:
warning: variable 'p' set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>