ALSA: emu10k1: Fix card shortname string buffer overflow

Some models provide too long string for the shortname that has 32bytes
including the terminator, and it results in a non-terminated string
exposed to the user-space.  This isn't too critical, though, as the
string is stopped at the succeeding longname string.

This patch fixes such entries by dropping "SB" prefix (it's enough to
fit within 32 bytes, so far).  Meanwhile, it also changes strcpy()
with strlcpy() to make sure that this kind of problem won't happen in
future, too.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>