IMPORT: plock: always expose the inline version of the lock wait function

IMPORT: plock: always expose the inline version of the lock wait function

Doing so will allow to expose the time spent in certain highly
contended functions, which can be desirable for more accurate CPU
profiling. For example this could be done in locking functions that
are already not inlined so that they are the ones being reported as
those consuming the CPU instead of just pl_wait_unlock_long().

This is plock upstream commit 7505c2e2c8c4aa0ab8f52a2288e1334ae6412be4.