uml: fix infinite mconsole loop

This patch takes care of a problem with the stopping code.

The function inside the while condition returns 0 to signify a problem.  A
problem could be for example a bad command or a bad version of the mconsole
client.  A bad command would terminate the stopping loop and resume the
kernel.  This is a problem.

A better solution is to make the loop infinite and don't leave it until we are
explicitly told to.
Signed-off-by: NKarol Swietlicki <magotari@gmail.com>
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/um/drivers/mconsole_kern.c

@@ -305,7 +305,9 @@ void mconsole_stop(struct mc_request *req)
 	deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
 	os_set_fd_block(req->originating_fd, 1);
 	mconsole_reply(req, "stopped", 0, 0);
-	while (mconsole_get_request(req->originating_fd, req)) {
+	for (;;) {
+		if (!mconsole_get_request(req->originating_fd, req))
+			continue;
 		if (req->cmd->handler == mconsole_go)
 			break;
 		if (req->cmd->handler == mconsole_stop) {