linux-user: correct msgrcv()

All parameters must be swapped before the call of do_msgrcv().

Allow faked (debian fakeroot daemon) to work properly.

WITHOUT this patch:

$ faked-sysv --foreground --debug
using 1723744788 as msg key
msg_key=1723744788
1723744788:431
FAKEROOT: msg=131072, key=1723744788
FAKEROOT: r=-1, received message type=-150996052, message=-160219330
FAKEROOT, get_msg: Bad address
r=14, EINTR=4
fakeroot: clearing up message queues and semaphores, signal=-1
fakeroot: database save FAILED

WITH this patch:

$ faked-sysv --foreground --debug
using 1569385744 as msg key
msg_key=1569385744
1569385744:424
FAKEROOT: msg=0, key=1569385744
^C
fakeroot: clearing up message queues and semaphores, signal=2
fakeroot: database save FAILED

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

linux-user/syscall.c

@@ -2897,7 +2897,7 @@ static inline abi_long do_msgrcv(int msqid, abi_long msgp,
         return -TARGET_EFAULT;
 
     host_mb = g_malloc(msgsz+sizeof(long));
-    ret = get_errno(msgrcv(msqid, host_mb, msgsz, tswapal(msgtyp), msgflg));
+    ret = get_errno(msgrcv(msqid, host_mb, msgsz, msgtyp, msgflg));
 
     if (ret > 0) {
         abi_ulong target_mtext_addr = msgp + sizeof(abi_ulong);
@@ -3189,7 +3189,7 @@ static abi_long do_ipc(unsigned int call, int first,
                     break;
                 }
 
-                ret = do_msgrcv(first, tmp->msgp, second, tmp->msgtyp, third);
+                ret = do_msgrcv(first, tswapal(tmp->msgp), second, tswapal(tmp->msgtyp), third);
 
                 unlock_user_struct(tmp, ptr, 0);
                 break;