qemu-log: correct help text for -d cpu

This doesn't just dump CPU state on translation but on every block
entrance.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-4-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

util/log.c

@@ -120,7 +120,7 @@ const QEMULogItem qemu_log_items[] = {
     { CPU_LOG_EXEC, "exec",
       "show trace before each executed TB (lots of logs)" },
     { CPU_LOG_TB_CPU, "cpu",
-      "show CPU state before block translation" },
+      "show CPU registers before entering a TB (lots of logs)" },
     { CPU_LOG_MMU, "mmu",
       "log MMU-related activities" },
     { CPU_LOG_PCALL, "pcall",