commands/legacycfg: Avoid closing file twice

commands/legacycfg: Avoid closing file twice

An internal (at Red Hat) static soure code scan detected an
use-after-free scenario:

  Error: USE_AFTER_FREE (CWE-416):
  grub-2.06/grub-core/commands/legacycfg.c:194: freed_arg: "grub_file_close" frees "file".
  grub-2.06/grub-core/commands/legacycfg.c:201: deref_arg: Calling "grub_file_close" dereferences freed pointer "file".
  #  199|         if (!args)
  #  200|   	{
  #  201|-> 	  grub_file_close (file);
  #  202|   	  grub_free (suffix);
  #  203|   	  grub_free (entrysrc);

So, remove the extra file close call.

Signed-off-by: Leo Sandoval <lsandova@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>