[Coverity CID :195905]Control flow issues in /arch/x86_64/core/x86_64.c

[aasthagr]

Static code scan issues seen in File: /arch/x86_64/core/x86_64.c
Category: Control flow issues
Function: _cpu_start
Component: Architectures
CID: 195905
Please fix or provide comments to square it off in coverity in the link: https://scan9.coverity.com/reports.htm#v32951/p12996

[andyross]

Similar to #14394, it's a false positive. It doesn't like

if (cpu == 0) {
...
} else if (cpu < CONFIG_MP_NUM_CPUS) {

When CONFIG_MP_NUM_CPUS is 1, as is the default in master right now. But it's a configurable, and it's not always 1, just happens to be in whatever configuration was passed to coverity.