ALSA: rme96: Delete two error messages for a failed memory allocation in snd_rme96_probe()

Omit extra messages for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>