char: rename chr_close/chr_free

The function is used to free the backend opaque pointer, let's name it
accordingly.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-23-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/spice-qemu-char.c b/spice-qemu-char.c
index 351fcaa..930b8c5 100644
--- a/spice-qemu-char.c
+++ b/spice-qemu-char.c
@@ -199,7 +199,7 @@
     return read_bytes;
 }
 
-static void spice_chr_close(struct CharDriverState *chr)
+static void spice_chr_free(struct CharDriverState *chr)
 {
     SpiceCharDriver *s = chr->opaque;
 
@@ -289,7 +289,7 @@
     chr->opaque = s;
     chr->chr_write = spice_chr_write;
     chr->chr_add_watch = spice_chr_add_watch;
-    chr->chr_close = spice_chr_close;
+    chr->chr_free = spice_chr_free;
     chr->chr_set_fe_open = set_fe_open;
     chr->explicit_be_open = true;
     chr->chr_fe_event = spice_chr_fe_event;