mac80211: Remove redundant assignment to ret

mac80211: Remove redundant assignment to ret

Variable 'ret' is set to -ENODEV 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:

net/mac80211/debugfs_netdev.c:60:2: warning: Value stored to 'ret' 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>
Link: https://lore.kernel.org/r/1619774483-116805-1-git-send-email-yang.lee@linux.alibaba.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>