CpuSet: Return void from CLR

CPU_CLR_S is documented to return void, but CpuSet::CLR was using it as a bool.
This happened to compile with glibc, but is wrong in general.

The return value of CLR is never used, so return void instead of bool.
CpuSet is an internal class.

https://man7.org/linux/man-pages/man3/CPU_SET.3.html

PiperOrigin-RevId: 704991349
Change-Id: I67ab5469055a298111fd452ce63ca4c6f2682387

tcmalloc/internal/cpu_utils.h

@@ -38,7 +38,7 @@ class CpuSet {
   bool IsSet(int cpu) const {
     return CPU_ISSET_S(cpu, kCpuSetBytes, cpu_set_.data());
   }
-  bool CLR(int cpu) { return CPU_CLR_S(cpu, kCpuSetBytes, cpu_set_.data()); }
+  void CLR(int cpu) { CPU_CLR_S(cpu, kCpuSetBytes, cpu_set_.data()); }
   int Count() const { return CPU_COUNT_S(kCpuSetBytes, cpu_set_.data()); }
 
   // Find the index of the first set CPU. Returns -1 if none are set.