nvme: host: fix double-free of struct nvme_id_ns in ns_update_nuse()

In the Linux kernel, the following vulnerability has been resolved:

nvme: host: fix double-free of struct nvme_id_ns in ns_update_nuse()

When nvme_identify_ns() fails, it frees the pointer to the struct nvme_id_ns before it returns. However, ns_update_nuse() calls kfree() for the pointer even when nvme_identify_ns() fails. This results in KASAN double-free, which was observed with blktests nvme/045 with proposed patches [1] on the kernel v6.8-rc7. Fix the double-free by skipping kfree() when nvme_identify_ns() fails.