nvmet: fix error return code in nvmet_file_ns_enable()

Fix to return error code -ENOMEM from the memory alloc fail error
handling case instead of 0, as done elsewhere in this function.

Fixes: d5eff33ee6 ("nvmet: add simple file backed ns support")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.e>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/io-cmd-file.c

@@ -49,14 +49,18 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns)
 	ns->bvec_cache = kmem_cache_create("nvmet-bvec",
 			NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
 			0, SLAB_HWCACHE_ALIGN, NULL);
-	if (!ns->bvec_cache)
+	if (!ns->bvec_cache) {
+		ret = -ENOMEM;
 		goto err;
+	}
 
 	ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
 			mempool_free_slab, ns->bvec_cache);
 
-	if (!ns->bvec_pool)
+	if (!ns->bvec_pool) {
+		ret = -ENOMEM;
 		goto err;
+	}
 
 	return ret;
 err: