cifs: fix wksidarr declaration to be big-endian friendly

The current definition of wksidarr works fine on little endian arches
(since cpu_to_le32 is a no-op there), but on big-endian arches, it fails
to compile with this error:

error: braced-group within expression allowed only inside a function

The problem is that this static declaration has cpu_to_le32 embedded
within it, and that expands into a function macro.  We need to use
__constant_cpu_to_le32() instead.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>