cocci: avoid "should ... be a metavariable" warnings
Since [1] running "make coccicheck" has resulted in [2] being emitted to the *.log files for the "spatch" run, and in the case of "make coccicheck-test" we'd emit these to the user's terminal. Nothing was broken as a result, but let's refactor the relevant rules to eliminate the ambiguity between a possible variable and an identifier. 1. 0e6550a2c63 (cocci: add a index-compatibility.pending.cocci, 2022-11-19) 2. warning: line 257: should active_cache be a metavariable? warning: line 260: should active_cache_changed be a metavariable? warning: line 263: should active_cache_tree be a metavariable? warning: line 271: should active_nr be a metavariable? Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>