util-linux: fix mount(8) helpers arg order with musl.

Before this patch mount(8) would execute something like:

	 /sbin/mount.helper src dest <opts>

After this patch:

	/sbin/mount.helper <opts> src dest

The reason is that musl does not reorder args to check for options,
so that options must appear before real arguments to make this work.

This makes zfs work correctly on musl.

Thanks to @chneukirchen for help in finding the issue.

srcpkgs/util-linux/patches/fix-musl-2.patch

@@ -11,3 +11,43 @@ Fixes rendering issue with chsh
  	if (sz == -1)
  		return NULL;
 
+--- libmount/src/context_mount.c.orig	2016-01-12 17:33:25.902659537 +0100
++++ libmount/src/context_mount.c	2016-01-12 17:34:31.198503965 +0100
+@@ -605,27 +605,27 @@ static int exec_helper(struct libmnt_con
+ 		type = mnt_fs_get_fstype(cxt->fs);
+ 
+ 		args[i++] = cxt->helper;		/* 1 */
+-		args[i++] = mnt_fs_get_srcpath(cxt->fs);/* 2 */
+-		args[i++] = mnt_fs_get_target(cxt->fs);	/* 3 */
+ 
+ 		if (mnt_context_is_sloppy(cxt))
+-			args[i++] = "-s";		/* 4 */
++			args[i++] = "-s";		/* 2 */
+ 		if (mnt_context_is_fake(cxt))
+-			args[i++] = "-f";		/* 5 */
++			args[i++] = "-f";		/* 3 */
+ 		if (mnt_context_is_nomtab(cxt))
+-			args[i++] = "-n";		/* 6 */
++			args[i++] = "-n";		/* 4 */
+ 		if (mnt_context_is_verbose(cxt))
+-			args[i++] = "-v";		/* 7 */
++			args[i++] = "-v";		/* 5 */
+ 		if (o) {
+-			args[i++] = "-o";		/* 8 */
+-			args[i++] = o;			/* 9 */
++			args[i++] = "-o";		/* 6 */
++			args[i++] = o;			/* 7 */
+ 		}
+ 		if (type
+ 		    && strchr(type, '.')
+ 		    && !endswith(cxt->helper, type)) {
+-			args[i++] = "-t";		/* 10 */
+-			args[i++] = type;		/* 11 */
++			args[i++] = "-t";		/* 8 */
++			args[i++] = type;		/* 9 */
+ 		}
++		args[i++] = mnt_fs_get_srcpath(cxt->fs);/* 10 */
++		args[i++] = mnt_fs_get_target(cxt->fs);	/* 11 */
+ 		args[i] = NULL;				/* 12 */
+ 		for (i = 0; args[i]; i++)
+ 			DBG(CXT, ul_debugobj(cxt, "argv[%d] = \"%s\"",

srcpkgs/util-linux/template

@@ -1,7 +1,7 @@
 # Template file for 'util-linux'
 pkgname=util-linux
 version=2.27.1
-revision=2
+revision=3
 short_desc="Miscellaneous linux utilities"
 maintainer="Juan RP <xtraeme@voidlinux.eu>"
 homepage="https://www.kernel.org/pub/linux/utils/util-linux/"