[Eva] Fixes the computation of the total number of functions in the summary.

src/plugins/value/utils/value_results.ml

...racle/issue_55_iter_over_unregistered_function.res.oracle

tests/idct/oracle/ieee_1180_1990.res.oracle

tests/journal/oracle/control.0.res.oracle

tests/journal/oracle/control.1.res.oracle

tests/journal/oracle/control2.res.oracle

tests/journal/oracle/control2_sav.res

tests/journal/oracle/intra.res.oracle

tests/metrics/oracle/func_ptr.0.res.oracle

tests/metrics/oracle/func_ptr.1.res.oracle

tests/metrics/oracle/libc.0.res.oracle

tests/metrics/oracle/libc.1.res.oracle

tests/metrics/oracle/reach.res.oracle

tests/metrics/oracle/unreachable.res.oracle

tests/misc/oracle/bts1201.res.oracle

tests/saveload/oracle/callbacks_initial.res

tests/syntax/oracle/loop-case-switch-for-unroll.0.res.oracle

tests/syntax/oracle/loop-case-switch-for-unroll.1.res.oracle

tests/syntax/oracle/loop-case-switch-for-unroll.2.res.oracle

tests/value/oracle/summary.0.res.oracle