ssb: Remove redundant assignment to err

ssb: Remove redundant assignment to err

Variable 'err' is set to zero but this value is never read as it is
overwritten with a new value later on, hence it is a redundant
assignment and can be removed.

Clean up the following clang-analyzer warning:

drivers/ssb/main.c:1306:3: warning: Value stored to 'err' is never read
[clang-analyzer-deadcode.DeadStores]
drivers/ssb/main.c:1312:3: warning: Value stored to 'err' is never read
[clang-analyzer-deadcode.DeadStores]

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Michael Büsch <m@bues.ch>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1619693230-108804-1-git-send-email-yang.lee@linux.alibaba.com