chrt: support passing `-p 0` to operate on self

Specifying a PID of 0 for the -p option of chrt would previously result
in a "number 0... not in range" error. Now, it means instead that the
calling process (i.e. chrt itself) should be operated on; this is to be
consistent with the behavior of util-linux's version of chrt.

function                                             old     new   delta
chrt_main                                            462     474     +12

Signed-off-by: Zuo An <zuoan.penguin@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

0 files changed, 0 insertions, 0 deletions