common/pkg/cgroups: Remove unused cpuset handler

The cpuset handler only had an empty Stat method that returned nil,
providing no functionality. Remove the handler entirely along with the
unused CPUset and CPUAcct controller constants which were remnants from
cgroups v1.

Signed-off-by: Lokesh Mandvekar <[email protected]>

Author: lsm5

common/pkg/cgroups/cgroups_linux.go

@@ -50,10 +50,6 @@ const (
 	cgroupRoot = "/sys/fs/cgroup"
 	// CPU is the cpu controller.
 	CPU = "cpu"
-	// CPUAcct is the cpuacct controller.
-	CPUAcct = "cpuacct"
-	// CPUset is the cpuset controller.
-	CPUset = "cpuset"
 	// Memory is the memory controller.
 	Memory = "memory"
 	// Pids is the pids controller.
@@ -67,7 +63,6 @@ var handlers map[string]controllerHandler
 func init() {
 	handlers = map[string]controllerHandler{
 		CPU:    getCPUHandler(),
-		CPUset: getCpusetHandler(),
 		Memory: getMemoryHandler(),
 		Pids:   getPidsHandler(),
 		Blkio:  getBlkioHandler(),