[PATCH 8/9] perf record: Fix poll return value propagation

If the perf record command is interrupted in record__mmap_read_all function, the 'done' is set and err has the latest poll return value, which is most likely positive number (= number of pollfds ready to read). This 'positive err' is then propagated to the exit code, resulting in not finishing

[PATCH 8/9] perf record: Fix poll return value propagation

If the perf record command is interrupted in record__mmap_read_all function, the 'done' is set and err has the latest poll return value, which is most likely positive number (= number of pollfds ready to read). This 'positive err' is then propagated to the exit code, resulting in not finishing