ALSA: compress_core: integer overflow in snd_compr_allocate_buffer()

These are 32 bit values that come from the user, we need to check for
integer overflows or we could end up allocating a smaller buffer than
expected.

Change-Id: I487be18c8df75cb925bc181c82f4151d4761dfaa
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>