pt: Inline PT packet no logging test

On larger decodes the packet logging showed up
as hot functions (5+%) even when disabled. The problem
was doing two function calls just to decide
to do nothing.

Inline the no logging test into the caller.

Improves decoding performance on a range of traces
by 3-4%

Signed-off-by: Andi Kleen <ak@linux.intel.com>