dmaengine: shdma: synchronize RCU before freeing, simplify spinlock
dmaengine: shdma: synchronize RCU before freeing, simplify spinlock

List elements, deleted using list_del_rcu(), cannot be freed without
synchronising RCU. Further, the spinlock, used to protect the RCU
writer, is called in process context, so, we don't have to save flags.

Signed-off-by: Guennadi Liakhovetski <50875182aae23d69ca7738697596f18a14e926fc@gmx.de>
Signed-off-by: Paul Mundt <38b52dbb5f0b63d149982b6c5de788ec93a89032@linux-sh.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas