Make valgrind happy on db read

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@1812 65c4cc65-6c06-0410-ace0-fbb531ad65f3

db.c

@@ -135,7 +135,7 @@ int ast_db_put(const char *family, const char *keys, char *value)
 
 int ast_db_get(const char *family, const char *keys, char *value, int valuelen)
 {
-	char fullkey[256];
+	char fullkey[256]="";
 	DBT key, data;
 	int res;