chan_alloc: Fix missing break statement

Fixes: Coverity CID 1261354
diff --git a/openbsc/src/libbsc/chan_alloc.c b/openbsc/src/libbsc/chan_alloc.c
index 51bd76f..9936ac7 100644
--- a/openbsc/src/libbsc/chan_alloc.c
+++ b/openbsc/src/libbsc/chan_alloc.c
@@ -116,6 +116,7 @@
 			case GSM_PCHAN_SDCCH8_SACCH8C:
 			case GSM_PCHAN_SDCCH8_SACCH8C_CBCH:
 				from = 1; to = 1;
+				break;
 			case GSM_PCHAN_TCH_F:
 			case GSM_PCHAN_TCH_H:
 				from = 1; to = 7;