Fix function comments based on best practices from Effective Go

src/novmm/machine/errors.go

@@ -43,7 +43,7 @@ var PciCapabilityMismatch = errors.New("Capability mismatch!")
 // UART errors.
 var UartUnknown = errors.New("Unknown COM port.")
 
-// Driver errors.
+// DriverUnknown: Driver errors.
 func DriverUnknown(name string) error {
 	return errors.New(fmt.Sprintf("Unknown driver: %s", name))
 }

src/novmm/plan9/unpack.go

@@ -21,7 +21,7 @@ import (
 	"log"
 )
 
-// Creates a Fcall value from the on-the-wire representation. If
+// Unpack: Creates a Fcall value from the on-the-wire representation. If
 // dotu is true, reads 9P2000.u messages. Returns the unpacked message,
 // error and how many bytes from the buffer were used by the message.
 func Unpack(