platform/mellanox: mlxreg-lc: Fix coverity warning

Fix smatch warning:
drivers/platform/mellanox/mlxreg-lc.c:866 mlxreg_lc_probe() warn: passing zero to 'PTR_ERR'
by removing 'err = PTR_ERR(regmap)'.

Fixes: b4b830a3 ("platform/mellanox: mlxreg-lc: Fix error flow and extend verbosity")
Reported-by: Nkernel test robot <lkp@intel.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NVadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20220823201937.46855-2-vadimp@nvidia.comReviewed-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>

drivers/platform/mellanox/mlxreg-lc.c

@@ -863,7 +863,6 @@ static int mlxreg_lc_probe(struct platform_device *pdev)
 	if (err) {
 		dev_err(&pdev->dev, "Failed to sync regmap for client %s at bus %d at addr 0x%02x\n",
 			data->hpdev.brdinfo->type, data->hpdev.nr, data->hpdev.brdinfo->addr);
-		err = PTR_ERR(regmap);
 		goto regcache_sync_fail;
 	}