The perror() calls do not make much sense with libdbus functions and
wpa_printf() would really be used for all error printing anyway. In
addition, many of the error messages on out-of-memory cases are not
really of much use, so they were removed. This is also cleaning up
some of the error path handling to avoid duplicated code.
These cannot be NULL, so there is no point in checking for that. In
addition, the accessor function for this is just making the code harder
to understand.
These header files are included outside the dbus subdirectory and there
is not really any need to force the libdbus dbus/dbus.h header file to
be included into these files.
