ck_spinlock: Add ck_spinlock_dec_init operation.
ck_spinlock: Get rid of MCS context initializers.

They are unnecessary, legacy from older versions.
ck_spinlock: Add ck_spinlock_mcs_init operation.
ck_spinlock: Retab (whitespace).
ck_spinlock: Retab (whitespace).

Accidentally had Haskell vim modeline set.