[PATCH v2] lock/semaphore: Avoid an unnecessary deadlock within up()

[Byungchul Park]

change from v1 to v2
- remove unnecessary overhead by the redundant spin(un)lock.

Since I faced a infinite recursive printk() bug, I've tried to propose
patches the title of which is "lib/spinlock_debug.c: prevent a recursive
cycle in the debug code". But I noticed the root problem cannot be fixed
by that, through some discussion thanks to Sergey and Peter. So I focused
on preventing the deadlock.

-----8<-----