rpm: Drop unnecessary BuildRequires

We've recently stopped checking for the presence of various
commands at build time, which means that we no longer need
to have the corresponding packages installed in the build
environment.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

libvirt.spec.in

@@ -371,12 +371,7 @@ BuildRequires: sanlock-devel >= 2.4
 BuildRequires: libpcap-devel >= 1.5.0
 BuildRequires: libnl3-devel
 BuildRequires: libselinux-devel
-# For modprobe
-BuildRequires: kmod
 BuildRequires: cyrus-sasl-devel
-BuildRequires: polkit >= 0.112
-# For mount/umount in FS driver
-BuildRequires: util-linux
     %if %{with_qemu}
 # For managing ACLs
 BuildRequires: libacl-devel
@@ -387,10 +382,6 @@ BuildRequires: /usr/bin/qemu-img
     %if %{with_nbdkit}
 BuildRequires: libnbd-devel
     %endif
-# For LVM drivers
-BuildRequires: lvm2
-# For pool type=iscsi
-BuildRequires: iscsi-initiator-utils
     %if %{with_storage_iscsi_direct}
 # For pool type=iscsi-direct
 BuildRequires: libiscsi-devel
@@ -430,11 +421,6 @@ BuildRequires: libwsman-devel >= 2.6.3
 BuildRequires: audit-libs-devel
 BuildRequires: systemtap-sdt-devel
 BuildRequires: /usr/bin/dtrace
-# For mount/umount in FS driver
-BuildRequires: util-linux
-    %if %{with_numad}
-BuildRequires: numad
-    %endif
     %if %{with_wireshark}
 BuildRequires: wireshark-devel
     %endif