[PATCH V2] util: Remove redundant checks in the openpty()

[AlexChen]

As we can see from the following function call stack, amaster and aslave
can not be NULL: char_pty_open() -> qemu_openpty_raw() -> openpty().
In addition, according to the API specification for openpty():
https://www.gnu.org/software/libc/manual/html_node/Pseudo_002dTerminal-Pairs.html,
the arguments name, termp and winp can all be NULL, but arguments amaster or 
aslave
can not be NULL.
Finally, amaster and aslave has been dereferenced at the beginning of the 
openpty().
So the checks on amaster and aslave in the openpty() are redundant. Remove them.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 util/qemu-openpty.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/util/qemu-openpty.c b/util/qemu-openpty.c
index eb17f5b0bc..427f43a769 100644
--- a/util/qemu-openpty.c
+++ b/util/qemu-openpty.c
@@ -80,10 +80,9 @@ static int openpty(int *amaster, int *aslave, char *name,
             (termp != NULL && tcgetattr(sfd, termp) < 0))
                 goto err;

-        if (amaster)
-                *amaster = mfd;
-        if (aslave)
-                *aslave = sfd;
+        *amaster = mfd;
+        *aslave = sfd;
+
         if (winp)
                 ioctl(sfd, TIOCSWINSZ, winp);

-- 
2.19.1