fix comments for ClearRlimitNofileCache

Signed-off-by: lifubang <lifubang@acmcoder.com>

libcontainer/system/linux.go

@@ -19,14 +19,15 @@ import (
 //go:linkname syscallOrigRlimitNofile syscall.origRlimitNofile
 var syscallOrigRlimitNofile atomic.Pointer[syscall.Rlimit]
 
-// As reported in issue #4195, the new version of go runtime(since 1.19)
-// will cache rlimit-nofile. Before executing execve, the rlimit-nofile
-// of the process will be restored with the cache. In runc, this will
-// cause the rlimit-nofile setting by the parent process for the container
-// to become invalid. It can be solved by clearing this cache. But
-// unfortunately, go stdlib doesn't provide such function, so we need to
-// link to the private var `origRlimitNofile` in package syscall to hack.
+// ClearRlimitNofileCache is to clear go runtime's nofile rlimit cache.
 func ClearRlimitNofileCache() {
+	// As reported in issue #4195, the new version of go runtime(since 1.19)
+	// will cache rlimit-nofile. Before executing execve, the rlimit-nofile
+	// of the process will be restored with the cache. In runc, this will
+	// cause the rlimit-nofile setting by the parent process for the container
+	// to become invalid. It can be solved by clearing this cache. But
+	// unfortunately, go stdlib doesn't provide such function, so we need to
+	// link to the private var `origRlimitNofile` in package syscall to hack.
 	syscallOrigRlimitNofile.Store(nil)
 }