Windows: Restore console mode on set mode failure

SetConsoleMode() on input handles appears to remember invalid bits that
were set, causing problems for other programs (such as xcopy.exe) trying
to set the console mode after docker.exe has exited. Always restore
the input console mode on set failure.

Signed-off-by: John Starks <jostarks@microsoft.com>

pkg/term/term_windows.go

@@ -44,9 +44,11 @@ func StdStreams() (stdIn io.ReadCloser, stdOut, stdErr io.Writer) {
 		if err = winterm.SetConsoleMode(fd, mode|enableVirtualTerminalInput); err != nil {
 			emulateStdin = true
 		} else {
-			winterm.SetConsoleMode(fd, mode)
 			vtInputSupported = true
 		}
+		// Unconditionally set the console mode back even on failure because SetConsoleMode
+		// remembers invalid bits on input handles.
+		winterm.SetConsoleMode(fd, mode)
 	}
 
 	fd = os.Stdout.Fd()