nvmet: remove redundant module prefix

This patch removes the redundant module prefix used in the pr_err() when
nvmet_get_smart_log_nsid() failed to find the namespace provided as a part
of smart-log command.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>