cciss: fix memory leak

There's a memory leak in the cciss driver.

in alloc_cciss_hba() we may leak sizeof(ctlr_info_t) bytes if a
call to alloc_disk(1 << NWD_SHIFT) fails.
This patch should fix the issue.

Spotted by the Coverity checker.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>