LU-5541 lustreapi: only export the API symbols

LU-5541 lustreapi: only export the API symbols

By default, all kind of symbols are exported from the library (dump,
libcfs_ukuc_start, l_ioctl, set_ioctl_dump, ...), which may create
external conflicts. Use the linker version-script options to only
export the API symbols, and prevent the export of internal symbols.

Only the symbols declared in the global section of liblustreapi.map
will be seen by applications.

Test-Parameters: trivial

Change-Id: I4fc2febd2528fc85f546426e08e3ab67e1305c40
Signed-off-by: frank zago <fzago@cray.com>
Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-on: https://review.whamcloud.com/30865
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>