Switch to xorriso (instead of genisoimage)

Upstream prefers it since:

  commit 174a0caf7eaf1943360f9d8f714f466ea7449d90
  Author: Richard W.M. Jones <rjones@redhat.com>
  Date:   Sat Apr 3 17:15:34 2021 +0100

    iso: Pick xorriso in preference to genisoimage or mkisofs.

    See this Debian page explaining the situation with genisoimage:
    https://wiki.debian.org/genisoimage

nbdkit.spec

@@ -51,7 +51,7 @@ ExclusiveArch:  x86_64
 
 Name:           nbdkit
 Version:        1.29.3
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        NBD server
 
 License:        BSD
@@ -96,7 +96,7 @@ BuildRequires:  libnbd-devel >= 1.3.11
 BuildRequires:  libssh-devel
 BuildRequires:  e2fsprogs, e2fsprogs-devel
 %if !0%{?rhel}
-BuildRequires:  genisoimage
+BuildRequires:  xorriso
 BuildRequires:  rb_libtorrent-devel
 %endif
 BuildRequires:  bash-completion
@@ -335,7 +335,7 @@ Summary:        Virtual ISO 9660 plugin for %{name}
 License:        BSD
 
 Requires:       %{name}-server%{?_isa} = %{version}-%{release}
-Requires:       genisoimage
+Requires:       xorriso
 
 
 %description iso-plugin
@@ -1246,6 +1246,9 @@ export LIBGUESTFS_TRACE=1
 
 
 %changelog
+* Tue Nov 02 2021 Richard W.M. Jones <rjones@redhat.com> - 1.29.3-2
+- Switch to xorriso (instead of genisoimage)
+
 * Thu Oct 28 2021 Richard W.M. Jones <rjones@redhat.com> - 1.29.3-1
 - New upstream development version 1.29.3