common: Drop log.h from common header

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 7fae383..28f98d4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -6,6 +6,7 @@
  */
 
 #include "btrfs.h"
+#include <log.h>
 #include <malloc.h>
 #include <memalign.h>