tcmur: Correct the cmd lba exceed check condition
tcmur: Correct the cmd lba exceed check condition

For the old check condition:
lba >= num_lbas || lba + sectors > num_lbas
When the lba + sectors > num_lbas will always contain possible lba
>= num_lbas, so it could be ignored here.

And for very large capacity backend devices or files(rare but possible),
the lba + sectors will exceed the max len of the lba type's capacity.

Signed-off-by: Xiubo Li <67e5e1ee902b4e67bce18ea43d9c4b0430ce5e6c@cmss.chinamobile.com>

lxbsz/tcmu-runner,agrover/tcmu-runner,open-iscsi/tcmu-runner,liuy/tcmu-runner,open-iscsi/tcmu-runner