sd: Remember to reset .expecting_acmd on reset.

Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>

hw/sd.c

diff --git a/hw/sd.c b/hw/sd.c
index 2b8ebe4..07eb263 100644
--- a/hw/sd.c
+++ b/hw/sd.c
@@ -422,6 +422,7 @@
     sd->size = size;
     sd->blk_len = 0x200;
     sd->pwd_len = 0;
+    sd->expecting_acmd = 0;
 }
 
 static void sd_cardchange(void *opaque, bool load)