nvme-fabrics: use consistent zeroout pattern

Remove zeroout memeset call & zeroout local variable cmd at the time
of declaration in nvmf_ref_read32() similar to what we have done in
nvmf_reg_read64(), nvmf_reg_write32(), nvmf_connect_admin_queue(), and
nvmf_connect_io_queue().

Signed-off-by: Chaitanya Kulkarni <[e-mail]>
Reviewed-by: Keith Busch <[e-mail]>
Signed-off-by: Christoph Hellwig <[e-mail]>

drivers/nvme/host/fabrics.c

···
  */
 int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
 {
-	struct nvme_command cmd;
+	struct nvme_command cmd = { };
 	union nvme_result res;
 	int ret;
 
-	memset(&cmd, 0, sizeof(cmd));
 	cmd.prop_get.opcode = nvme_fabrics_command;
 	cmd.prop_get.fctype = nvme_fabrics_type_property_get;
 	cmd.prop_get.offset = cpu_to_le32(off);