The value stored to ptr in the calculations this patch removes is not
used, so the calculation and the assignment can be removed.

Cleans up the following clang-analyzer warning:

drivers/net/can/softing/softing_main.c:279:3: warning: Value stored to
'ptr' is never read [clang-analyzer-deadcode.DeadStores].

drivers/net/can/softing/softing_main.c:242:3: warning: Value stored to
'ptr' is never read [clang-analyzer-deadcode.DeadStores].

Link: https://lore.kernel.org/r/1619520767-80948-1-git-send-email-jiapeng.chong@linux.alibaba.comReported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>