platform: fix error handling in event_handler_recvmsgs()

@abort_parsing is set TRUE at two places, which also explicitly
set @err to something. We don't want to reset @err and got to the
next @hdr. Instead error out first.

src/platform/nm-linux-platform.c

@@ -5697,11 +5697,12 @@ continue_reading:
 		}
 
 		event_seq_check (platform, msg, seq_result);
-		err = 0;
-		hdr = nlmsg_next (hdr, &n);
 
 		if (abort_parsing)
 			goto out;
+
+		err = 0;
+		hdr = nlmsg_next (hdr, &n);
 	}
 
 	if (multipart) {