ALSA: dice: assign converted data to the same type of variable

In former commit, u32 data was assigned to __be32 variable instead of an
int variable. This is not enough solution because it still causes sparse
warnings.

dice.c:80:23: warning: incorrect type in assignment (different base types)
dice.c:80:23:    expected restricted __be32 [usertype] value
dice.c:80:23:    got unsigned int
dice.c:81:21: warning: restricted __be32 degrades to integer
dice.c:81:46: warning: restricted __be32 degrades to integer

This commit fixes this bug.

Fixes: 7c2d4c0c('ALSA: dice: Split transaction functionality into a file')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>