btrfs-progs: fix musl build

srcpkgs/btrfs-progs/patches/musl-compat.patch

@@ -21,3 +21,23 @@
  	if (!(f = fopen(p, "r"))) {
  		if (errno == ENOENT)
  			/*
+--- mkfs/common.c.orig	2017-03-08 13:23:24.000000000 +0000
++++ mkfs/common.c	2017-03-09 06:24:26.356552024 +0000
+@@ -18,6 +18,7 @@
+ #include <uuid/uuid.h>
+ #include <blkid/blkid.h>
+ #include <fcntl.h>
++#include <limits.h>
+ #include "ctree.h"
+ #include "disk-io.h"
+ #include "volumes.h"
+--- convert/source-ext2.c.orig	2017-03-08 13:23:24.000000000 +0000
++++ convert/source-ext2.c	2017-03-09 06:27:45.991562323 +0000
+@@ -16,6 +16,7 @@
+ 
+ #if BTRFSCONVERT_EXT2
+ 
++#include <linux/limits.h>
+ #include "kerncompat.h"
+ #include "disk-io.h"
+ #include "transaction.h"