Fix CPU hotplug section mismatches

Fix CPU hotplug section mismatches

Get rid of the following section mismatches:

WARNING: /home/jang/temp/lttng-modules-2.2.0-r0/git/lttng-tracer.o(.text+0x19dc0): Section mismatch in reference from the function lttng_add_perf_counter_to_ctx() to the function .cpuinit.text:lttng_perf_counter_cpu_hp_callback()
The function lttng_add_perf_counter_to_ctx() references
the function __cpuinit lttng_perf_counter_cpu_hp_callback().
This is often because lttng_add_perf_counter_to_ctx lacks a __cpuinit
annotation or the annotation of lttng_perf_counter_cpu_hp_callback is wrong.

WARNING: /home/jang/temp/lttng-modules-2.2.0-r0/git/lib/lttng-lib-ring-buffer.o(.text+0x1204): Section mismatch in reference from the function channel_backend_init() to the function .cpuinit.text:lib_ring_buffer_cpu_hp_callback()
The function channel_backend_init() references
the function __cpuinit lib_ring_buffer_cpu_hp_callback().
This is often because channel_backend_init lacks a __cpuinit
annotation or the annotation of lib_ring_buffer_cpu_hp_callback is wrong.

WARNING: /home/jang/temp/lttng-modules-2.2.0-r0/git/lib/lttng-lib-ring-buffer.o(.text+0x269c): Section mismatch in reference from the function channel_create() to the function .cpuinit.text:lib_ring_buffer_cpu_hp_callback()
The function channel_create() references
the function __cpuinit lib_ring_buffer_cpu_hp_callback().
This is often because channel_create lacks a __cpuinit
annotation or the annotation of lib_ring_buffer_cpu_hp_callback is wrong.

WARNING: /home/jang/temp/lttng-modules-2.2.0-r0/git/lib/lttng-lib-ring-buffer.o(.text+0x4a1c): Section mismatch in reference from the function channel_iterator_init() to the function .cpuinit.text:channel_iterator_cpu_hotplug()
The function channel_iterator_init() references
the function __cpuinit channel_iterator_cpu_hotplug().
This is often because channel_iterator_init lacks a __cpuinit
annotation or the annotation of channel_iterator_cpu_hotplug is wrong.

Signed-off-by: Jan Glauber <jan.glauber@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>