linux-user: Tidy TARGET_NR_rt_sigaction

Initialize variables instead of elses.
Use an else instead of a goto.
Add braces.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210422230227.314751-8-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/syscall.c

@@ -9060,32 +9060,26 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
             target_ulong sigsetsize = arg4;
             target_ulong restorer = 0;
 #endif
-            struct target_sigaction *act;
-            struct target_sigaction *oact;
+            struct target_sigaction *act = NULL;
+            struct target_sigaction *oact = NULL;
 
             if (sigsetsize != sizeof(target_sigset_t)) {
                 return -TARGET_EINVAL;
             }
-            if (arg2) {
-                if (!lock_user_struct(VERIFY_READ, act, arg2, 1)) {
-                    return -TARGET_EFAULT;
-                }
-            } else {
-                act = NULL;
+            if (arg2 && !lock_user_struct(VERIFY_READ, act, arg2, 1)) {
+                return -TARGET_EFAULT;
             }
-            if (arg3) {
-                if (!lock_user_struct(VERIFY_WRITE, oact, arg3, 0)) {
-                    ret = -TARGET_EFAULT;
-                    goto rt_sigaction_fail;
+            if (arg3 && !lock_user_struct(VERIFY_WRITE, oact, arg3, 0)) {
+                ret = -TARGET_EFAULT;
+            } else {
+                ret = get_errno(do_sigaction(arg1, act, oact, restorer));
+                if (oact) {
+                    unlock_user_struct(oact, arg3, 1);
                 }
-            } else
-                oact = NULL;
-            ret = get_errno(do_sigaction(arg1, act, oact, restorer));
-	rt_sigaction_fail:
-            if (act)
+            }
+            if (act) {
                 unlock_user_struct(act, arg2, 0);
-            if (oact)
-                unlock_user_struct(oact, arg3, 1);
+            }
         }
         return ret;
 #ifdef TARGET_NR_sgetmask /* not on alpha */