[tracker] libtracker-data: Fix potential NULL pointer dereference

[Sam Thursfield <sthursfield src gnome org>]

commit bde247a5e60712b1efb5235414bb9cb9bab86334
Author: Sam Thursfield <sam afuera me uk>
Date:   Sat Apr 4 17:05:01 2020 +0200

    libtracker-data: Fix potential NULL pointer dereference
    
    This was introduced in !202 and detected by Coverity after merging
    (CID 1492490).

 src/libtracker-data/tracker-db-manager.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/libtracker-data/tracker-db-manager.c b/src/libtracker-data/tracker-db-manager.c
index cca9350d7..d257c33a6 100644
--- a/src/libtracker-data/tracker-db-manager.c
+++ b/src/libtracker-data/tracker-db-manager.c
@@ -636,7 +636,9 @@ tracker_db_manager_new (TrackerDBManagerFlags   flags,
        }
 
        if (need_to_create) {
-               *first_time = TRUE;
+               if (first_time) {
+                       *first_time = TRUE;
+               }
 
                if ((db_manager->flags & TRACKER_DB_MANAGER_IN_MEMORY) == 0 &&
                     !tracker_file_system_has_enough_space (db_manager->data_dir, 
TRACKER_DB_MIN_REQUIRED_SPACE, TRUE)) {