timers: Get rid of del_singleshot_timer_sync()

mainline inclusion
from mainline-v6.2-rc1
commit 9a5a3056
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7R8WG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9a5a305686971f4be10c6d7251c8348d74b3e014



--------------------------------

del_singleshot_timer_sync() used to be an optimization for deleting timers
which are not rearmed from the timer callback function.

This optimization turned out to be broken and got mapped to
del_timer_sync() about 17 years ago.

Get rid of the undocumented indirection and use del_timer_sync() directly.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Link: https://lore.kernel.org/r/20221123201624.706987932@linutronix.de



 Conflicts:
	net/sunrpc/xprt.c
Signed-off-by: Yu Liao <liaoyu15@huawei.com>