uprobes/core: Make instruction tables volatile

uprobes/core: Make instruction tables volatile

Some versions of gcc spits a warning about the asm operand for
test_bit and also causes the first long of the instruction table
to be output.

Fix is similar to 7115e3fc on arch/x86/kernel/kprobes.c

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Stone <jistone@redhat.com>
Link: http://lkml.kernel.org/r/20120222091535.15880.12502.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>