[PATCH] net: fix err_cast.cocci warnings

From: kernel test robot <redacted>

drivers/net/wwan/wwan_core.c:208:9-16: WARNING: ERR_CAST can be used with wwandev


 Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))

Generated by: scripts/coccinelle/api/err_cast.cocci

CC: Loic Poulain <redacted>
Reported-by: kernel test robot <redacted>
Signed-off-by: kernel test robot <redacted>
---

url:    https://github.com/0day-ci/linux/commits/Loic-Poulain/net-Add-a-WWAN-subsystem/20210402-220002
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git bd78980be1a68d14524c51c4b4170782fada622b

 wwan_core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c

@@ -205,7 +205,7 @@ struct wwan_port *wwan_create_port(struc
 	 */
 	wwandev = wwan_create_dev(parent);
 	if (IS_ERR(wwandev))
-		return ERR_PTR(PTR_ERR(wwandev));
+		return ERR_CAST(wwandev);
 
 	/* A port is exposed as character device, get a minor */
 	minor = ida_alloc_range(&minors, 0, WWAN_MAX_MINORS - 1, GFP_KERNEL);