pcmcia: annotate cb_alloc with __ref

cb_alloc() uses a function (pci_scan_slot) that will be annotated __devinit.

Annotate cb_alloc() with __ref to tell modpost to ignore this reference.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>