Fix error when flashing with uf2conv.py

util/uf2conv.py

@@ -246,10 +246,13 @@ def list_drives():
 
 
 def write_file(name, buf):
+    try:
         with open(name, "wb") as f:
             f.write(buf)
         print("Wrote %d bytes to %s" % (len(buf), name))
-
+    except IOError as e:
+        print(f"Failed to write to {name}: {e}")
+        print("Still may have wrote %d bytes to %s" % (len(buf), name))
 
 def load_families():
     # The expectation is that the `uf2families.json` file is in the same