Patch fixes a build problem with CONFIG_X86_VSMP. The vSMP bits probably
gathered some fuzz on its way to mainline, and safe_halt() which was outside
the #endif (CONFIG_X86_VSMP) somehow got inside the !CONFIG_X86_VSMP condition,
hence being undefined and breaking CONFIG_X86_VSMP builds. Patch takes
safe_halt() and halt() macros out of the #endif