i4l: leak in eicon/idifunc.c

coverity spotted a possible leak in the idifunc.c file (bug id #1252), in
um_new_card(), if the diva_user_mode_idi_create_adapter() fails, we dont
free the memory allocated for card

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Acked-by: Armin Schindler <armin@melware.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>