Use cell name for btor bad state props when it is a public name Signed-off-by: Clifford Wolf <clifford@clifford.at>

diff --git a/backends/btor/btor.cc b/backends/btor/btor.cc
index 2babd45..c1da4b1 100644
--- a/backends/btor/btor.cc
+++ b/backends/btor/btor.cc

@@ -1070,15 +1070,11 @@
 					bad_properties.push_back(nid_en_and_not_a);
 				} else {
 					int nid = next_nid++;
-
-					string infostr =
-						cell->attributes.count("\\src")
-						? cell->attributes.at("\\src")
-						.decode_string()
-						.c_str()
-						: log_id(cell);
-
-					std::replace(infostr.begin(), infostr.end(), ' ', '_');
+					string infostr = log_id(cell);
+					if (infostr[0] == '$' && cell->attributes.count("\\src")) {
+						infostr = cell->attributes.at("\\src").decode_string().c_str();
+						std::replace(infostr.begin(), infostr.end(), ' ', '_');
+					}
 					btorf("%d bad %d %s\n", nid, nid_en_and_not_a, infostr.c_str());
 				}