staging: rtl8723bs: fix another spelling mistake

I found one more spelling mistake in a DBG_8192C debug message,
replace "avaliable" with "available", add some spacing between
text and a number and split overly long line

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>