cxgb4: Assign boolean values to a bool variable

Fix the following coccicheck warnings:

./drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:5142:2-33:
WARNING: Assignment of 0/1 to bool variable.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Link: https://lore.kernel.org/r/1611126111-22079-1-git-send-email-abaci-bugfix@linux.alibaba.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>