Omit an extra message for a memory allocation failure in this function
(please note that there can be only one wm8505fb device in the system).

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>