target/i386: Tidy hw_breakpoint_remove

Since cpu_breakpoint and cpu_watchpoint are in a union,
the code should access only one of them.

Signed-off-by: Dmitry Voronetskiy <davoronetskiy@gmail.com>
Message-Id: <20210613180838.21349-1-davoronetskiy@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/i386/tcg/sysemu/bpt_helper.c

@@ -109,9 +109,9 @@ static void hw_breakpoint_remove(CPUX86State *env, int index)
 
     case DR7_TYPE_DATA_WR:
     case DR7_TYPE_DATA_RW:
-        if (env->cpu_breakpoint[index]) {
+        if (env->cpu_watchpoint[index]) {
             cpu_watchpoint_remove_by_ref(cs, env->cpu_watchpoint[index]);
-            env->cpu_breakpoint[index] = NULL;
+            env->cpu_watchpoint[index] = NULL;
         }
         break;