tools/exitsnoop: Use task->real_parent instead of task->parent (#4025)
tools/exitsnoop: Use task->real_parent instead of task->parent (#4025)

Use task->real_parent instead of task->parent (when one process being traced, the tracer becomes its parent, so use task->real_parent is more accurate).
Unify PID column width (at most 7 chars) #3915, try to unify PID/PPID/TID column width (at most 7 chars).
iovisor/bcc,iovisor/bcc,iovisor/bcc,iovisor/bcc,iovisor/bcc