cosmetic: logging.h: fix indentation

Change-Id: Ia7f43e061275da1a8233f90df173d1ae18691964
diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 21b98f6..0078425 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -294,7 +294,7 @@
 
 /*! structure representing a logging target */
 struct log_target {
-        struct llist_head entry;		/*!< linked list */
+	struct llist_head entry;		/*!< linked list */
 
 	/*! Internal data for filtering */
 	int filter_map;