btrfs-tools:Fix multithreaded building

Fixes bug: [YOCTO #1524]

Fixes this error with make -j:
btrfsctl.c
| i586-poky-linux-gcc  -m32   -march=i586
--sysroot=/intel/poky/builds/world/tmp/sysroots/qemux86
-Wp,-MMD,./.btrfsctl.o.d,-MT,btrfsctl.o -Wall -D_FILE_OFFSET_BITS=64
-D_FORTIFY_SOURCE=2 -O2 -pipe -g -feliminate-unused-debug-types -c
btrfsctl.c
| btrfsctl.c:37:21: fatal error: version.h: No such file or directory
| compilation terminated.
| btrfslabel.c:40:21: fatal error: version.h: No such file or directory
| compilation terminated.

(From OE-Core rev: 3ebc06c2f011da95fd6bed74c9e27b2148011ee7)

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/btrfs-tools/btrfs-tools/fix_race_condition_with_multithreaded_make.patch

@@ -0,0 +1,36 @@
+Upstream-Status: Pending
+
+Fix makefile for multithreaded (make -j ) building.
+
+btrfsctl.c
+| i586-poky-linux-gcc  -m32   -march=i586 --sysroot=/intel/poky/builds/world/tmp/sysroots/qemux86 -Wp,-MMD,./.btrfsctl.o.d,-MT,btrfsctl.o -Wall -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -O2 -pipe -g -feliminate-unused-debug-types -c btrfsctl.c
+| btrfsctl.c:37:21: fatal error: version.h: No such file or directory
+| compilation terminated.
+| btrfslabel.c:40:21: fatal error: version.h: No such file or directory
+| compilation terminated.
+
+Signed-Off-By: Nitin A Kamble <nitin.a.kamble@intel.com>
+2012/01/02
+
+Index: git/Makefile
+===================================================================
+--- git.orig/Makefile
++++ git/Makefile
+@@ -26,14 +26,13 @@ else
+ 	check = ls
+ endif
+ 
+-.c.o:
++%.o: %.c version.h
+ 	$(check) $<
+ 	$(CC) $(DEPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c $<
+ 
++all: $(progs) manpages
+ 
+-all: version $(progs) manpages
+-
+-version:
++version.h: version.sh
+ 	bash version.sh
+ 
+ btrfs: $(objects) btrfs.o btrfs_cmds.o scrub.o

meta/recipes-devtools/btrfs-tools/btrfs-tools_git.bb

@@ -16,10 +16,12 @@ SRC_URI = "git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git;p
 
 S = "${WORKDIR}/git"
 
-PR = "r4"
+PR = "r5"
 
 SRC_URI += " file://fix_use_of_gcc.patch \
-	 file://weak-defaults.patch "
+	 file://weak-defaults.patch \
+	 file://fix_race_condition_with_multithreaded_make.patch "
+
 SRC_URI[md5sum] = "78b1700d318de8518abfaab71f99a885"
 SRC_URI[sha256sum] = "1285774e0cb72984fac158dd046c8d405324754febd30320cd31e459253e4b65"