Remove redundant check from tui_refresh_frame_and_register_information

tui_refresh_frame_and_register_information checks 'from_stack' in a
block that's already guarded by a 'from_stack' check.  This patch
removes the redundant check.

Tested-By: Tom de Vries <tdevries@suse.de>
Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Approved-By: Andrew Burgess <aburgess@redhat.com>