LU-4199 libcfs: add wrapper of dump_trace()

LU-4199 libcfs: add wrapper of dump_trace()

dump_trace() is a X86 specific function. It will cause
compilation failure if the architecture is not X86. A more
general function dump_stack() should be called under that
environment.

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Change-Id: I8a5fffa6dec15dc8c779a22e24c10b364c77f9a0
Reviewed-on: http://review.whamcloud.com/8872
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>