linux-user: do_setsockopt: eliminate goto in switch for SO_SNDTIMEO

There's identical code for SO_SNDTIMEO and SO_RCVTIMEO, currently
implemented using an ugly goto into another switch case.  Eliminate
that using arithmetic if, making code flow more natural.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Message-Id: <20240331100737.2724186-5-mjt@tls.msk.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/syscall.c

@@ -2301,12 +2301,10 @@ static abi_long do_setsockopt(int sockfd, int level, int optname,
     case TARGET_SOL_SOCKET:
         switch (optname) {
         case TARGET_SO_RCVTIMEO:
+        case TARGET_SO_SNDTIMEO:
         {
                 struct timeval tv;
 
-                optname = SO_RCVTIMEO;
-
-set_timeout:
                 if (optlen != sizeof(struct target_timeval)) {
                     return -TARGET_EINVAL;
                 }
@@ -2315,13 +2313,12 @@ static abi_long do_setsockopt(int sockfd, int level, int optname,
                     return -TARGET_EFAULT;
                 }
 
-                ret = get_errno(setsockopt(sockfd, SOL_SOCKET, optname,
+                ret = get_errno(setsockopt(sockfd, SOL_SOCKET,
+                                optname == TARGET_SO_RCVTIMEO ?
+                                    SO_RCVTIMEO : SO_SNDTIMEO,
                                 &tv, sizeof(tv)));
                 return ret;
         }
-        case TARGET_SO_SNDTIMEO:
-                optname = SO_SNDTIMEO;
-                goto set_timeout;
         case TARGET_SO_ATTACH_FILTER:
         {
                 struct target_sock_fprog *tfprog;