Zero-initialize unset fields of `struct fuse_operations`.
<https://github.com/kedazo/fuse-7z-ng/pull/8>
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -195,7 +195,7 @@ main (int argc, char **argv)
         mkdir(param.mountpoint, 0750);
     }
 
-    struct fuse_operations fuse7z_oper;
+    struct fuse_operations fuse7z_oper = {0};
     fuse7z_oper.init = fuse7z_init;
     fuse7z_oper.destroy = fuse7z_destroy;
     fuse7z_oper.readdir = fuse7z_readdir;