Stop dracut 35network-manager from running nm-initrd-generator

kexec-tools depends on dracut's 35network-manager module which will
call nm-initrd-generator. We don't want nm-initrd-generator to generate
connection profiles since we  will copy them from 1st kernel to
kdump kernel initramfs. NetworkManager >= 1.35.2 won't generate connection
profiles if there's a connection dir with rd.neednet. For Fedora/RHEL,
this connection dir is /etc/NetworkManager/system-connections. For the
details, please refer to the NetworkManager commit 79885656d3
("initrd: don't add a connection if there's a connection dir with
rd.neednet") [1]. Before the release of NetworkManager >= 1.35.2, we
need to mask /usr/libexec/nm-initrd-generator.

[1] https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1010

Signed-off-by: Coiby Xu <coxu@redhat.com>
Reviewed-by: Thomas Haller <thaller@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>

dracut-module-setup.sh

@@ -465,6 +465,11 @@ kdump_install_nmconnections() {
             exit 1
         fi
     done <<< "$(nmcli -t -f device,filename connection show --active)"
+
+    # Stop dracut 35network-manger to calling nm-initrd-generator.
+    # Note this line of code can be removed after NetworkManager >= 1.35.2
+    # gets released.
+    echo > "${initdir}/usr/libexec/nm-initrd-generator"
 }
 
 kdump_setup_bridge() {