[ALSA] sound: emu10k1x.c fix shadowed variable warnings

enable in these contexts refers specifically to intr enable, as
per the two functions it is found in.  Use intr_enable instead.
sound/pci/emu10k1/emu10k1x.c:330:15: warning: symbol 'enable' shadows an earlier one
sound/pci/emu10k1/emu10k1x.c:53:12: originally declared here
sound/pci/emu10k1/emu10k1x.c:341:15: warning: symbol 'enable' shadows an earlier one
sound/pci/emu10k1/emu10k1x.c:53:12: originally declared here

instead of shadowing, use cap_voice as we test for the capture
voice in this statement.
sound/pci/emu10k1/emu10k1x.c:798:25: warning: symbol 'pvoice' shadows an earlier one
sound/pci/emu10k1/emu10k1x.c:787:24: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>