dont actually reset the current page header
small tiny fix
=== RUN TestCSmith
all_test.go:1658: --bitfields --max-nested-struct-level 10 --no-const-pointers --no-consts --no-packed-struct --no-volatile-pointers --no-volatiles --paranoid -s 3100949894
all_test.go:1762: files 24, bytes 2,160,054, ok 24 in 3m25.201831389s
--- PASS: TestCSmith (205.20s)
PASS
ok modernc.org/ccgo/v3/lib 205.213s