genl: genl_ctrl_grp_by_name: fix retval in case group id not found
genl: genl_ctrl_grp_by_name: fix retval in case group id not found

Now the return value in case group id is not find is 0. Change it to
return -NLE_OBJ_NOTFOUND which makes more sense. This should not break
anything because genl_ctrl_grp_by_name is static and called only from
genl_ctrl_resolve_grp. genl_ctrl_resolve_grp already might return
-NLE_OBJ_NOTFOUND.

Signed-off-by: Jiri Pirko <fa978af6b66b63204eae0f383d59a9477a8acf5e@redhat.com>

houstar/libnl,congwang/libnl,tklauser/libnl,teto/libnl_old,houstar/libnl,cyclops8456/libnl3,cfriedt/libnl,karlhiramoto/libnl,baloo/libnl,dsahern/libnl,tgraf/libnl,thom311/libnl,houstar/libnl,mshirley/libnl,cyclops8456/libnl3,HolyShitMan/libnl-1,dsahern/libnl,mshirley/libnl,tgraf/libnl,UnicronNL/libnl3,honsys/libnl,cfriedt/libnl,socketpair/libnl,UnicronNL/libnl3,vyos/libnl3,HolyShitMan/libnl-1,teto/libnl_old,cyclops8456/libnl3,dsahern/libnl,teto/libnl_old,claudelee/libnl,baloo/libnl,teto/libnl_old,thom311/libnl,baloo/libnl,socketpair/libnl,karlhiramoto/libnl,kolyshkin/libnl,claudelee/libnl,vyos/libnl3,vyos/libnl3,thom311/libnl,claudelee/libnl,UnicronNL/libnl3,tklauser/libnl,congwang/libnl,Distrotech/libnl,kolyshkin/libnl,chitranshi/libnl,houstar/libnl,greearb/libnl-ct,kolyshkin/libnl,mshirley/libnl,cfriedt/libnl,socketpair/libnl,dsahern/libnl,chitranshi/libnl,karlhiramoto/libnl,cfriedt/libnl,honsys/libnl,karlhiramoto/libnl,claudelee/libnl,greearb/libnl-ct,vyos/libnl3,cyclops8456/libnl3,honsys/libnl,mshirley/libnl,HolyShitMan/libnl-1,kolyshkin/libnl,tklauser/libnl,tklauser/libnl,chitranshi/libnl,congwang/libnl,baloo/libnl,honsys/libnl,UnicronNL/libnl3,Distrotech/libnl,Distrotech/libnl,greearb/libnl-ct,congwang/libnl,HolyShitMan/libnl-1,tgraf/libnl,chitranshi/libnl,Distrotech/libnl,tgraf/libnl