blockdev: Rename drive_init(), drive_uninit() to drive_new(), drive_del()

"Init" and "uninit" suggest the functions don't allocate / free
storage.  But they do.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/vl.c b/vl.c
index ac0e3d7..be69c7f 100644
--- a/vl.c
+++ b/vl.c
@@ -1074,7 +1074,7 @@
 {
     BlockInterfaceType *block_default_type = opaque;
 
-    return drive_init(opts, *block_default_type) == NULL;
+    return drive_new(opts, *block_default_type) == NULL;
 }
 
 static int drive_enable_snapshot(QemuOpts *opts, void *opaque)
@@ -1098,7 +1098,7 @@
     if (snapshot) {
         drive_enable_snapshot(opts, NULL);
     }
-    if (!drive_init(opts, type)) {
+    if (!drive_new(opts, type)) {
         exit(1);
     }
 }