staging: gs_fpgaboot: pr_err() strings should end with newlines

pr_err() messages should end with a new-line to avoid other messages
being concatenated.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>