lib: Make coverity happy about close

The error condition handled both failure to open
and a fstat failure.  Just double check that the close
is appropriate to call.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

lib/elf_py.c

@@ -1140,7 +1140,8 @@ static PyObject *elffile_load(PyTypeObject *type, PyObject *args,
 	fd = open(filename, O_RDONLY | O_NOCTTY);
 	if (fd < 0 || fstat(fd, &st)) {
 		PyErr_SetFromErrnoWithFilename(PyExc_OSError, filename);
-		close(fd);
+		if (fd > 0)
+			close(fd);
 		goto out;
 	}
 	w->len = st.st_size;