Fix compilation warning caused by copy_from_user ret not handled.
Fix compilation warning:
/__w/openwrt/openwrt/openwrt/build_dir/target-mips-openwrt-linux-musl_musl/linux-lantiq_ase/ltq-atm-ase/ltq-atm/ltq_atm.c: In function 'ppe_ioctl':
/__w/openwrt/openwrt/openwrt/build_dir/target-mips-openwrt-linux-musl_musl/linux-lantiq_ase/ltq-atm-ase/ltq-atm/ltq_atm.c:341:17: error: ignoring return value of 'copy_from_user' declared with attribute 'warn_unused_result' [-Werror=unused-result]
341 | copy_from_user(&mib_vcc, arg, sizeof(mib_vcc));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
--- /dev/null
+--- a/ltq_atm.c
++++ b/ltq_atm.c
+@@ -338,7 +338,8 @@ static int ppe_ioctl(struct atm_dev *dev
+ break;
+
+ case PPE_ATM_MIB_VCC: /* VCC related MIB */
+- copy_from_user(&mib_vcc, arg, sizeof(mib_vcc));
++ if (copy_from_user(&mib_vcc, arg, sizeof(mib_vcc)))
++ return -EFAULT;
+ conn = find_vpivci(mib_vcc.vpi, mib_vcc.vci);
+ if (conn >= 0) {
+ mib_vcc.mib_vcc.aal5VccCrcErrors = g_atm_priv_data.conn[conn].aal5_vcc_crc_err;