Fix typo

Signed-off-by: Yuanhong Peng <[email protected]>

Author: Yuanhong Peng

libcontainer/process_linux.go

@@ -32,7 +32,7 @@ type parentProcess interface {
 	// wait waits on the process returning the process state.
 	wait() (*os.ProcessState, error)
 
-	// startTime return's the process start time.
+	// startTime returns the process start time.
 	startTime() (string, error)
 
 	signal(os.Signal) error