printk: Fix console_sem vs logbuf_lock unlock race

printk: Fix console_sem vs logbuf_lock unlock race

Fix up the fallout from commit 0b5e1c5255 ("printk: Release
console_sem after logbuf_lock").

The reason for unlocking the console_sem under the logbuf_lock
is that a concurrent printk() might fill up the buffer but fail
to acquire the console sem, resulting in a missed write to the
console until a subsequent console_sem acquire/release cycle.

Signed-off-by: Peter Zijlstra <[email protected]>
Cc: [email protected]
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Link: http://lkml.kernel.org/r/1308734409.1022.14.camel@twins
Signed-off-by: Ingo Molnar <[email protected]>