cifs: connect: style: Simplify bool comparison

Fix the following coccicheck warning:
./fs/cifs/connect.c:3740:6-21: WARNING: Comparison of 0/1 to bool
variable

Signed-off-by: YANG LI <abaci-bugfix@linux.alibaba.com>
Reported-by: Abaci <Robot&lt;abaci@linux.alibaba.com>
Signed-off-by: Steve French <stfrench@microsoft.com>