feat: check_for_err: show DMA halted/idle state

Also check for errors when example demo finishes

Author: patrislav1

example/demo_cpp/src/axi_dma_demo.cpp

@@ -150,7 +150,7 @@ int main(int argc, char* argv[]) {
             break;
         }
     }
-
+    axi_dma->check_for_errors();
     traffic_gen->stop();
 
     auto [counter_ok, counter_total] = fut.get();

src/UioAxiDmaIf.cpp

@@ -62,6 +62,14 @@ bool UioAxiDmaIf::check_for_errors() {
     bool has_errors = false;
 
     auto sr = s2mm_dmasr.rd();
+    if (sr.halted) {
+        BOOST_LOG_SEV(_lg, bls::warning) << "DMA Halted";
+    }
+
+    if (sr.idle) {
+        BOOST_LOG_SEV(_lg, bls::warning) << "DMA Idle";
+    }
+
     if (sr.dma_int_err) {
         has_errors = true;
         BOOST_LOG_SEV(_lg, bls::fatal) << "DMA Internal Error";