FS-11785 [mod_spandsp] fix dead assignments

src/mod/applications/mod_spandsp/mod_spandsp.c

@@ -473,7 +473,6 @@ void mod_spandsp_indicate_data(switch_core_session_t *session, switch_bool_t sel
 
 		if (locked) {
 			switch_core_session_rwunlock(target_session);
-			locked = 0;
 		}
 	}
 }

src/mod/applications/mod_spandsp/mod_spandsp_dsp.c

@@ -464,7 +464,6 @@ static switch_bool_t inband_dtmf_callback(switch_media_bug_t *bug, void *user_da
 				switch_resample_process(pvt->resampler, dp, (int) datalen / 2 / 1);
 				memcpy(dp, pvt->resampler->to, pvt->resampler->to_len * 2 * 1);
 				samples = pvt->resampler->to_len;
-				datalen = pvt->resampler->to_len * 2 * 1;
 			}
 
 			dtmf_rx(pvt->dtmf_detect, dp, samples);

src/mod/applications/mod_spandsp/mod_spandsp_fax.c

@@ -2061,12 +2061,10 @@ static switch_status_t t38_gateway_on_consume_media(switch_core_session_t *sessi
 
 	if (read_fd != FAX_INVALID_SOCKET) {
 		close(read_fd);
-		read_fd = FAX_INVALID_SOCKET;
 	}
 
 	if (write_fd != FAX_INVALID_SOCKET) {
 		close(write_fd);
-		write_fd = FAX_INVALID_SOCKET;
 	}