perf header: Don't pass struct perf_file_section to process_##_feat

perf header: Don't pass struct perf_file_section to process_##_feat

struct perf_file_section is used in process_##_feat as container for
size and offset in the file descriptor. These attributes are meaninful
in pipe-mode but struct perf_file_section is not.

Add offset and size variables to struct feat_fd to store
perf_file_section's values in file-mode. Later on, the same variables
can be reused for pipe-mode.

This patch does not change behavior.

Signed-off-by: David Carrillo-Cisneros <[email protected]>
Acked-by: David Ahern <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: He Kuang <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Simon Que <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>