tcg: Remove argument to tcg_prologue_init

We can load tcg_ctx just as easily within the callee.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

bsd-user/main.c

@@ -586,7 +586,7 @@ int main(int argc, char **argv)
      * generating the prologue until now so that the prologue can take
      * the real value of GUEST_BASE into account.
      */
-    tcg_prologue_init(tcg_ctx);
+    tcg_prologue_init();
 
     target_cpu_init(env, regs);