Make the ksymtab symbols for EXPORT_SYMBOL visible.
This prevents the LTO compiler from adding a .NUMBER prefix,
which avoids various problems in later export processing.

Cc: rusty@rustcorp.com.au
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>