ALSA: emu10k1: fix coding style for emu10k1_main.c

I fixed all of coding style errors and some warnings, now it is down to:
checkpatch.pl-0.24 --no-tree --file --strict --terse emu10k1_main.c
total: 0 errors, 62 warnings, 7 checks, 2075 lines checked
Signed-off-by: Vedran Miletic <rivanvx@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>