Some bit spinlocks are replaced with regular spinlock_t for PREEMPT_RT
using conditional (#ifdef'ed) code changes at the usage site. In contrast,
usage-site changes are not needed for the spinlock_t substitution.
-Instead, conditionals in header files and the core locking implemementation
+Instead, conditionals in header files and the core locking implementation
enable the compiler to do the substitution transparently.