ia64: fix module loading for gcc-5.4

Starting from gcc-5.4+ gcc generates MLX instructions in more cases to
refer local symbols:

    https://gcc.gnu.org/PR60465

That caused ia64 module loader to choke on such instructions:

    fuse: invalid slot number 1 for IMM64

The Linux kernel used to handle only case where relocation pointed to
slot=2 instruction in the bundle.  That limitation was fixed in linux by
commit 9c184a07 ("[IA64] Fix 2.6 kernel for the new ia64 assembler")
See

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

This change lifts the slot=2 restriction from the kernel module loader.

Tested on 'fuse' and 'btrfs' kernel modules.

Cc: Markus Elfring <elfring@users.sourceforge.net>
Cc: H J Lu <hjl.tools@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Bug: https://bugs.gentoo.org/601014


Tested-by: Émeric MASCHINO <emeric.maschino@gmail.com>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>