Remove redundant code

[yamt]

Found by clang-check. (the last one looks like a false-positive to me)

parson.c:995:17: warning: Value stored to 'buf' is never read buf += written; ^ ~~~~~~~ parson.c:1016:17: warning: Value stored to 'buf' is never read buf += written; ^ ~~~~~~~ parson.c:1834:24: warning: Array access (via field 'names') results in a null pointer dereference if (strcmp(object->names[i], name) == 0) { ^~~~~~~~~~~~~~~~ 3 warnings generated.