Omit padding in RC4_KEY on IA-64. The idea behind padding was to reserve

Omit padding in RC4_KEY on IA-64. The idea behind padding was to reserve
room for aligning of the key schedule itself [specific alignment is
required for future performance improvements], but OpenSSH "abuses"
our API by making copies and restoring RC4_KEY, thus ruining the
alignment and making it impossible to recover the key schedule.
PR: 1114