accel/tcg: Remove redundant case in store_atom_16

We handled the HAVE_ATOMIC128_RW case with atomic16_set at the top of
the function; the only thing left for a host without that support is
to fall through to cpu_loop_exit_atomic.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230916220151.526140-7-richard.henderson@linaro.org>

accel/tcg/ldst_atomicity.c.inc

@@ -1103,10 +1103,6 @@ static void store_atom_16(CPUState *cpu, uintptr_t ra,
         }
         break;
     case MO_128:
-        if (HAVE_ATOMIC128_RW) {
-            atomic16_set(pv, val);
-            return;
-        }
         break;
     default:
         g_assert_not_reached();