The current 'opus/opus.h' works if your opus.h is in /usr/include/opus, as
/usr/include is already in the header search path. If your opus header search
path is found via pkg-config, however, you will get something like this:
$ pkg-config --cflags opus
-I/usr/local/Cellar/opus/1.1/include/opus
Since this is pointing directly to include/opus, the 'opus/' prefix on the
header include directive will break.
Since 'opus.h' should work in both cases (as in both cases it will be
discovered via pkg-config), just use the simpler 'opus.h'.
Signed-off-by: Steven Noonan <steven@uplinklabs.net>
