btrfs-tools: fix symlink creation multiple times

The rule to create symlink in Makefile caused parallel issue:
$ make -j 40 DESTDIR=/image install BUILD_VERBOSE=1
...
  1     [LN]     libbtrfs.so.0
  2     [LN]     libbtrfs.so
  3 ln -s -f libbtrfs.so.0.1 libbtrfs.so.0
  4 ln -s -f libbtrfs.so.0.1 libbtrfs.so.0
  5 ln -s -f libbtrfs.so.0.1 libbtrfs.so
  6 ln -s -f libbtrfs.so.0.1 libbtrfs.so
...

It failed occasionally:
...
|symlinkat: couldn't stat 'git/libbtrfs.so' even though symlink
creation succeeded (No such file or directory).
|ln: failed to create symbolic link 'libbtrfs.so': No such file or directory
...

(From OE-Core rev: 9409c7e7202fe96b55f44a133ba68690bb192da2)

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/btrfs-tools/btrfs-tools/fix-symlink-creation-multiple-times.patch

@@ -0,0 +1,46 @@
+From 05ab78e9183575e38f342e05a056cb7bcd1e52e1 Mon Sep 17 00:00:00 2001
+From: Hongxu Jia <hongxu.jia@windriver.com>
+Date: Thu, 18 Feb 2016 20:41:28 -0500
+Subject: [PATCH] btrfs-progs: fix symlink creation multiple times
+
+The rule to create symlink in Makefile caused parallel issue:
+$ make -j 40 DESTDIR=/image install BUILD_VERBOSE=1
+...
+  1     [LN]     libbtrfs.so.0
+  2     [LN]     libbtrfs.so
+  3 ln -s -f libbtrfs.so.0.1 libbtrfs.so.0
+  4 ln -s -f libbtrfs.so.0.1 libbtrfs.so.0
+  5 ln -s -f libbtrfs.so.0.1 libbtrfs.so
+  6 ln -s -f libbtrfs.so.0.1 libbtrfs.so
+...
+
+It failed occasionally:
+...
+|symlinkat: couldn't stat 'git/libbtrfs.so' even though symlink
+creation succeeded (No such file or directory).
+|ln: failed to create symbolic link 'libbtrfs.so': No such file or directory
+...
+
+Upstream-Status: Submitted [linux-btrfs@vger.kernel.org]
+Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
+---
+ Makefile.in | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+diff --git a/Makefile.in b/Makefile.in
+index 1f4002e..16eeaf9 100644
+--- a/Makefile.in
++++ b/Makefile.in
+@@ -236,8 +236,7 @@ $(libs_static): $(libbtrfs_objects)
+ 
+ $(lib_links):
+ 	@echo "    [LN]     $@"
+-	$(Q)$(LN_S) -f libbtrfs.so.0.1 libbtrfs.so.0
+-	$(Q)$(LN_S) -f libbtrfs.so.0.1 libbtrfs.so
++	$(Q)$(LN_S) -f libbtrfs.so.0.1 $@
+ 
+ # keep intermediate files from the below implicit rules around
+ .PRECIOUS: $(addsuffix .o,$(progs))
+-- 
+1.9.1
+

meta/recipes-devtools/btrfs-tools/btrfs-tools_4.4.bb

@@ -15,6 +15,7 @@ DEPENDS = "util-linux attr e2fsprogs lzo acl"
 SRCREV = "21258fab2caeade405a15ba932d373b364aa6e8c"
 SRC_URI = "git://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git \
            file://fix-parallel.patch \
+           file://fix-symlink-creation-multiple-times.patch \
 "
 
 inherit autotools-brokensep pkgconfig