* Fix ps command CPU usage on Apple Silicon M1 macs. #4142
The cpu user and system times returned my libproc are not in
nanoseconds; they are in mach ticks units. This is not documented very
well. The convert from mach ticks to ns, the kernel provides a timebase
info function and datatype:
https://developer.apple.com/documentation/driverkit/3433733-mach_timebase_info
The commit makes the PS command work for me.
* Cargo fmt of previous commit.
* Clippy format suggestion
Co-authored-by: Ondrej Baudys <ondrej.baudys@nextgen.net>