Report file system type

Previously, only the file sizes were reported:

~~~
Filesystem                                             Size  Used Avail Use% Mounted on
/dev/mapper/luks-3aa4fbe3-5a19-4025-b70c-1d3038b76bd4  399G  9.1G  373G   3% /
/dev/mapper/luks-3aa4fbe3-5a19-4025-b70c-1d3038b76bd4  399G  9.1G  373G   3% /
~~~

Newly, also file system type will be reported:

~~~
Filesystem                                             Type   Size  Used Avail Use% Mounted on
/dev/mapper/luks-3aa4fbe3-5a19-4025-b70c-1d3038b76bd4  btrfs  399G  9.1G  373G   3% /
/dev/mapper/luks-3aa4fbe3-5a19-4025-b70c-1d3038b76bd4  btrfs  399G  9.1G  373G   3% /
~~~

This is useful in case file system influeces the build result.

Fixes #1263

mock/py/mockbuild/plugins/hw_info.py

@@ -47,7 +47,7 @@ def _unprivPreInitHook(self):
         out.write("\n\nMemory:\n")
         out.write(output)
 
-        cmd = ["/bin/df", "-H", self.buildroot.make_chroot_path(), self.config["cache_topdir"]]
+        cmd = ["/bin/df", "-H", "-T", self.buildroot.make_chroot_path(), self.config["cache_topdir"]]
         output = mockbuild.util.do(cmd, shell=False, returnOutput=True, raiseExc=False)
         out.write("\n\nStorage (chroot, cache_topdir):\n")
         out.write(output)