revision.h: turn rev_info.early_output back into an unsigned int

rev_info.early_output started out as an unsigned int in cdcefbc97 (Add "--early-output" log flag for interactive GUI use, 2007-11-03), but later it was turned into a single bit in a bit field in cc243c3ce (show: --ignore-missing, 2011-05-18) without explanation, though the code using it still expects it to be a regular integer type and uses it as a counter. Consequently, any even number given via '--early-output=<N>', or indeed a plain '--early-output' defaulting to 100 effectively disabled the feature. Turn rev_info.early_output back into its origin unsigned int data type, making '--early-output' work again. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>