libpayload/gdb: fix unused variable warning

input_underrun is defined but not used. A reasonably new compiler,
enabled warnings and warnings-as-error make the build break for no good
reason.

Change-Id: Ibeb7ba53aad5738938093ab7b34695c9c99c9afe
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/19482
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc@marcjonesconsulting.com>
1 file changed