convert mm_context_t semaphore to a mutex.
Signed-off-by: NLuiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>