rapidio: dereferencing an error pointer

Original patch: https://lkml.org/lkml/2016/8/4/32

If riocm_ch_alloc() fails then we end up dereferencing the error
pointer.

The problem is that we're not unwinding in the reverse order from how we
allocate things so it gets confusing.  I've changed this around so now
"ch" is NULL when we are done with it after we call riocm_put_channel().
That way we can check if it's NULL and avoid calling riocm_put_channel()
on it twice.

I renamed err_nodev to err_put_new_ch so that it better reflects what
the goto does.

Then because we had flipping things around, it means we don't neeed to
initialize the pointers to NULL and we can remove an if statement and
pull things in an indent level.

Link: http://lkml.kernel.org/r/20160805152406.20713-1-alexandre.bounine@idt.com


Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Barry Wood <barry.wood@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>