Update handling of cacheflush syscall with changes made in arch/arm
counterpart:
- return error to userspace when flushing syscall fails
- split user cache-flushing into interruptible chunks
- don't bother rounding to nearest vma
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
[will: changed internal return value from -EINTR to 0 to match arch/arm/]
Signed-off-by: Will Deacon <will.deacon@arm.com>