buildtools: filter out checked symbols for icc

buildtools: filter out checked symbols for icc

For some reason, ICC creates additional global symbols with a . which
triggers an error in the check that validates that symbols in the
experimental section are properly published in the map file of the
library. Filter them out.

Fixes: 3290ac14eb94 ("buildtools: detect discrepancies for experimental symbols")

Reported-by: Ferruh Yigit <ferruh.yigit@intel.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Tested-by: Ferruh Yigit <ferruh.yigit@intel.com>