backend/session: use "KMS" instead of "DRM" in log messages

Some DRM devices are not KMS-capable. DRM card nodes (also
known as DRM primary nodes) are created for render-only devices
as well. Let's just use "KMS" everywhere instead of "DRM" and
"DRM card".

backend/session/session.c

@@ -404,7 +404,7 @@ static ssize_t explicit_find_gpus(struct wlr_session *session,
 
 		ret[i] = session_open_if_kms(session, ptr);
 		if (!ret[i]) {
-			wlr_log(WLR_ERROR, "Unable to open %s as DRM device", ptr);
+			wlr_log(WLR_ERROR, "Unable to open %s as KMS device", ptr);
 		} else {
 			++i;
 		}
@@ -459,7 +459,7 @@ ssize_t wlr_session_find_gpus(struct wlr_session *session,
 
 	if (udev_enumerate_get_list_entry(en) == NULL) {
 		udev_enumerate_unref(en);
-		wlr_log(WLR_INFO, "Waiting for a DRM card device");
+		wlr_log(WLR_INFO, "Waiting for a KMS device");
 
 		struct find_gpus_add_handler handler = {0};
 		handler.listener.notify = find_gpus_handle_add;
@@ -470,7 +470,7 @@ ssize_t wlr_session_find_gpus(struct wlr_session *session,
 		while (!handler.added) {
 			int ret = wl_event_loop_dispatch(session->event_loop, (int)timeout);
 			if (ret < 0) {
-				wlr_log_errno(WLR_ERROR, "Failed to wait for DRM card device: "
+				wlr_log_errno(WLR_ERROR, "Failed to wait for KMS device: "
 					"wl_event_loop_dispatch failed");
 				udev_enumerate_unref(en);
 				return -1;