Long network interface names cause problems

[atis.elsts]

There is a potential crash when the length of an interface name is equal to IF_NAMESIZE. In this case the C string in the ifr_name field may not be null-terminated. This situation should be taken in account everywhere when the struct ifreq is used in the kernel and in the userspace.

To repeat: try to configure intarface alias with name '/dev/net/etherpci/0:123456789012':

ifconfig /dev/net/etherpci/0:123456789012 1.2.3.4

[axeld]

Since the kernel would only cut off the extra bytes, I've just fixed the userland tools to fail earlier with the "interface name too long" message in hrev37689.