[IA64] Fix 2.6 kernel for the new ia64 assembler

The new ia64 assembler uses slot 1 for the offset of a long (2-slot)
instruction and the old assembler uses slot 2. The 2.6 kernel assumes
slot 2 and won't boot when the new assembler is used:

http://sources.redhat.com/bugzilla/show_bug.cgi?id=1433

This patch will work with either slot 1 or 2.

Patch provided by H.J. Lu

Signed-off-by: Tony Luck <tony.luck@intel.com>