Update Btrfs files for in-kernel usage

btrfs had magic to put the chagneset id into a printk on module load.
This removes that from the Makefile and hardcodes the printk to print
"Btrfs"
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/Makefile

@@ -13,17 +13,12 @@ else
 # Normal Makefile
 
 KERNELDIR := /lib/modules/`uname -r`/build
-all: version
+all:
 	$(MAKE) -C $(KERNELDIR) M=`pwd` modules
 
-version:
-	bash version.sh
-
 modules_install:
 	$(MAKE) -C $(KERNELDIR) M=`pwd` modules_install
 clean:
 	$(MAKE) -C $(KERNELDIR) M=`pwd` clean
 
-tester:
-	$(MAKE) -C $(KERNELDIR) M=`pwd` tree-defrag.o transaction.o sysfs.o super.o root-tree.o inode-map.o inode-item.o inode.o file-item.o file.o extent_map.o disk-io.o ctree.o dir-item.o extent-tree.o
 endif

fs/btrfs/version.h

+#ifndef __BTRFS_VERSION_H
+#define __BTRFS_VERSION_H
+#define BTRFS_BUILD_VERSION "Btrfs"
+#endif