statedump: fix clang null dereference error

ctx->active can be null, and is checked elsewhere in the
same function. In another case, where 'ctx->active' gets
dereferenced, it needs to be validated before the loop
is hit.

Updates: bz#1622665
Change-Id: I4ec917e96c0756586fc7a74c76848bb9589a0293
Signed-off-by: Amar Tumballi <amarts@redhat.com>

libglusterfs/src/statedump.c

@@ -808,7 +808,7 @@ gf_proc_dump_info(int signum, glusterfs_ctx_t *ctx)
     if (!ctx)
         goto out;
 
-    if (ctx) {
+    if (ctx && ctx->active) {
         top = ctx->active->first;
         for (trav_p = &top->children; *trav_p; trav_p = &(*trav_p)->next) {
             brick_count++;