[PATCH] x86_64: Don't do broadcast IPIs when hotplug is enabled in flat mode.

The use of non-shortcut version of routines breaking CPU hotplug.  The option
to select this via cmdline also is deleted with the physflat patch, hence
directly placing this code under CONFIG_HOTPLUG_CPU.

We dont want to use broadcast mode IPI's when hotplug is enabled.  This causes
bad effects in send IPI to a cpu that is offline which can trip when the cpu
is in the process of being kicked alive.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>