Revert "rwsem: steal writing sem for better performance"

This reverts commit 8d5e27d646aa0a8a4e6d6adb620cb81bdf547eda.
Revert "rwsem-spinlock: let rwsem write lock stealable"

This reverts commit 65e65dde9cf5268f2cdb09d33c126c84dcce8c05.
Major changes to RWSEM algorithm

locking, rwsem: Annotate inner lock as raw
rwsem-spinlock: Implement writer lock-stealing for better scalability
rwsem: Implement writer lock-stealing for better scalability
rwsem: make the waiter type an enumeration rather than a bitmask
rwsem: shorter spinlocked section in rwsem_down_failed_common()
rwsem: move rwsem_down_failed_common code into rwsem_down_{read,write}_failed
rwsem: simplify rwsem_down_read_failed
rwsem: simplify rwsem_down_write_failed
rwsem: more agressive lock stealing in rwsem_down_write_failed
rwsem: use cmpxchg for trying to steal write lock
rwsem: avoid taking wait_lock in rwsem_down_write_failed
rwsem: skip initial trylock in rwsem_down_write_failed
rwsem: simplify __rwsem_do_wake
rwsem: implement support for write lock stealing on the fastpath
rwsem: do not block readers at head of queue if other readers are active
Signed-off-by: Michel Lespinasse <walken@google.com>