libsepol: silence false-positive -Wwrite-strings warning

When compiling with -Wwrite-strings, the compiler complains about
calling strs_add with a const char* value for a char* parameter
(DEFAULT_OBJECT is defined to "object_r"). Silence this warning by
casting the literal string to char*.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
1 file changed