semihosting: Use env more often in do_common_semihosting

We've already loaded cs->env_ptr into a local variable; use it.
Since env is unconditionally used, we don't need a dummy use.

Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

semihosting/arm-compat-semi.c

@@ -553,7 +553,6 @@ void do_common_semihosting(CPUState *cs)
     GuestFD *gf;
     int64_t elapsed;
 
-    (void) env; /* Used implicitly by arm lock_user macro */
     nr = common_semi_arg(cs, 0) & 0xffffffffU;
     args = common_semi_arg(cs, 1);
 
@@ -636,12 +635,12 @@ void do_common_semihosting(CPUState *cs)
         break;
 
     case TARGET_SYS_WRITEC:
-        qemu_semihosting_console_outc(cs->env_ptr, args);
+        qemu_semihosting_console_outc(env, args);
         common_semi_set_ret(cs, 0xdeadbeef);
         break;
 
     case TARGET_SYS_WRITE0:
-        ret = qemu_semihosting_console_outs(cs->env_ptr, args);
+        ret = qemu_semihosting_console_outs(env, args);
         common_semi_set_ret(cs, ret);
         break;
 
@@ -672,7 +671,7 @@ void do_common_semihosting(CPUState *cs)
         break;
 
     case TARGET_SYS_READC:
-        ret = qemu_semihosting_console_inc(cs->env_ptr);
+        ret = qemu_semihosting_console_inc(env);
         common_semi_set_ret(cs, ret);
         break;