fix: pkg/hwapi: close fd on each iteration in ReadMSR

Since the contents of MSRs is stored in ret anyways, we can make a syscall
to close a MSRs' fd, otherwise we are likely to hit the limit of open files
per process (i.e. 'ReadMSR - gomsr.MSR context aborted with: too many open
 files').

Signed-off-by: Michal Gorlas <michal.gorlas@9elements.com>

Author: micgor32

pkg/hwapi/msr.go

@@ -23,6 +23,7 @@ func (h HwAPI) ReadMSR(msr int64) []uint64 {
 			break
 		}
 		ret = append(ret, msrData)
+		msrCtx.Close()
 		count++
 	}