selftests:firmware: fixes a call to a wrong function name

 This is a patch to the tools/testing/selftests/firmware/fw_run_tests.sh
 file which fixes a bug which calls to a wrong function name,which in turn
 blocks the execution of certain tests.

Signed-off-by: Jeffrin Jose T <jeffrin@rajagiritech.edu.in>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>