Don't let the kernel parameters override the subvol for the snapshot (#85)

Previously, the kernel parameters came after the `rootflags=subvol=<snapshot>`
argument. This means that when the user's standard kernel parameters also
contain a `rootflags=subvol=<root>`, it will override the subvol flag of the
snapshot. So put the snapshot's subvol flag last.

41_snapshots-btrfs

@@ -208,7 +208,7 @@ make_menu_entries()
 		fi
 		echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
 		echo 'Loading Kernel: "${k}" ...'
-		linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
+		linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" rw ${kernel_parameters} rootflags=subvol=\""${snap_dir_name}"\""
 				if [[ -f "${boot_dir}"/"${u}" && "${i}" != "${prefix_i}-${kversion}-${alt_suffix_i}" ]] ; then
 					entry "\
 		echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'