perf intel-pt: Remove redundant initial_skip checks

'initial_skip' is checked inside the sample synthesis functions which means
it is actually being done twice for 'instructions' and 'transactions'
samples. Remove the redundant checks.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1495786658-18063-17-git-send-email-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>