ALSA: asihpi - fix return type of hpios_locked_mem_alloc()

This function returns zero or -ENOMEM, but because it's type is u16, the
-ENOMEM gets changed to 65524.  None of the callers care, but lets fix
it anyway as a cleanup.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>