LU-1347 style: removes obsolete EXPORT_SYMTAB macros v2

LU-1347 style: removes obsolete EXPORT_SYMTAB macros v2

EXPORT_SYMTAB is obsolete after 2.4 kernel, this patch removes
EXPORT_SYMTAB from the source code again.

Signed-off-by: Keith Mannthey <keith.mannthey@intel.com>
Change-Id: Idac9983d42b2c3e645def54628b6bc34d28aa3af
Reviewed-on: http://review.whamcloud.com/6739
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Peng Tao <bergwolf@gmail.com>
Reviewed-by: Liu Xuezhao <xuezhao.liu@emc.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>