Fix typo and comments related to the recent no-wait lock improvements

The argument of dontWait at the top of ProcSleep() was documented
backwards, and there was a typo in lock.c.

Thinkos in 2346df6.

Author: Will Mortensen
Reviewed-by: Jingxian Li, Michael Paquier
Discussion: https://postgr.es/m/CAMpnoC5f+eiS7tdy8PUpd_LacSTVT-pYpVooKfjHRQQmkHPZ2g@mail.gmail.com

Author: michaelpq

src/backend/storage/lmgr/lock.c

@@ -1060,7 +1060,7 @@ LockAcquireExtended(const LOCKTAG *locktag,
 
 		/*
 		 * Check the proclock entry status. If dontWait = true, this is an
-		 * expected case; otherwise, it will open happen if something in the
+		 * expected case; otherwise, it will only happen if something in the
 		 * ipc communication doesn't work correctly.
 		 */
 		if (!(proclock->holdMask & LOCKBIT_ON(lockmode)))

src/backend/storage/lmgr/proc.c

@@ -1054,8 +1054,8 @@ AuxiliaryPidGetProc(int pid)
  * at exit.
  *
  * Result: PROC_WAIT_STATUS_OK if we acquired the lock, PROC_WAIT_STATUS_ERROR
- * if not (if dontWait = true, this is a deadlock; if dontWait = false, we
- * would have had to wait).
+ * if not (if dontWait = true, we would have had to wait; if dontWait = false,
+ * this is a deadlock).
  *
  * ASSUME: that no one will fiddle with the queue until after
  *		we release the partition lock.