btrfs-progs: Update to 4.15

Compile tested on ar71xx

Signed-off-by: Rosen Penev <rosenp@gmail.com>

utils/btrfs-progs/Makefile

@@ -8,12 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=btrfs-progs
-PKG_VERSION:=4.14.1
+PKG_VERSION:=4.15
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-v$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@KERNEL/linux/kernel/people/kdave/btrfs-progs/
-PKG_HASH:=90c5b3a73d0a5194754bb148d362b4d2b0755527324c4e9d9fa0b4c15bb354dd
+PKG_HASH:=9e3528c60c76970b73297ea4b01bdc23a70c39c82d540b61cf07a7c0612339e9
 PKG_MAINTAINER:=Rosen Penev <rosenp@gmail.com>
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-v$(PKG_VERSION)