savevm: Reset last block info at beginning of each save

If we save more than once we need to reset the last block info or else
only the first save has the actual block info and each subsequent save
will only use continue flags, making them unloadable independently.

Found-by: Miguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/arch_init.c b/arch_init.c
index 47bb4b2..e0bd18c 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -104,10 +104,11 @@
     return 1;
 }
 
+static RAMBlock *last_block;
+static ram_addr_t last_offset;
+
 static int ram_save_block(QEMUFile *f)
 {
-    static RAMBlock *last_block = NULL;
-    static ram_addr_t last_offset = 0;
     RAMBlock *block = last_block;
     ram_addr_t offset = last_offset;
     ram_addr_t current_addr;
@@ -231,6 +232,8 @@
     if (stage == 1) {
         RAMBlock *block;
         bytes_transferred = 0;
+        last_block = NULL;
+        last_offset = 0;
 
         /* Make sure all dirty bits are set */
         QLIST_FOREACH(block, &ram_list.blocks, next) {