Changed log lock from 'quick' to 'basic' because this is an I/O lock.

Changed log lock from 'quick' to 'basic' because this is an I/O lock.

We cannot use a 'quick' lock (i.e. lock spinning on the CPU) for the log
lock because it can wait a lot on I/Os. Using a 'quick' lock leads to
eating the CPU for no good reason.

Example of 'pidstat' output when using various locks for log_lock:

- 'quick' lock and slow log file system (tail -f on the log file on XFS on RHEL 8)

04:15:11 PM   UID      TGID       TID    %usr %system    %CPU CPU  Command
04:15:21 PM   998     16431         -  100.00    4.20  100.00   2  unbound
04:15:21 PM   998         -     16431   31.00    1.00   32.00   2  |__unbound
04:15:21 PM   998         -     16432   31.30    0.80   32.10   0  |__unbound
04:15:21 PM   998         -     16433   30.20    1.40   31.60   1  |__unbound
04:15:21 PM   998         -     16434   30.70    1.00   31.70   3  |__unbound

- 'quick' lock and log file system being fast

04:15:40 PM   UID      TGID       TID    %usr %system   %CPU CPU  Command
04:15:50 PM   998     16431         -   10.00    1.60  11.60   1  unbound
04:15:50 PM   998         -     16431    2.50    0.50   3.00   1  |__unbound
04:15:50 PM   998         -     16432    2.30    0.40   2.70   3  |__unbound
04:15:50 PM   998         -     16433    2.70    0.30   3.00   0  |__unbound
04:15:50 PM   998         -     16434    2.60    0.40   3.00   2  |__unbound

- 'basic' lock (this commit) and slow log file system (tail -f on the log file on XFS on RHEL 8)

04:29:48 PM   UID      TGID       TID    %usr %system   %CPU CPU  Command
04:29:58 PM   998     11632         -    7.10   14.10  21.20   3  unbound
04:29:58 PM   998         -     11632    1.70    3.20   4.90   3  |__unbound
04:29:58 PM   998         -     11633    1.60    3.30   4.90   1  |__unbound
04:29:58 PM   998         -     11634    2.00    4.10   6.10   1  |__unbound
04:29:58 PM   998         -     11635    1.90    3.50   5.40   1  |__unbound

We can see in the above example, when 'basic' lock is used, that CPU
isn't consumed when log file system is slow.

Another reproducer scenario: put the log file on a NFS share with 'sync'
option.