Clarify that grub files aren't used on s390x in man page

Resolves: #2105118
Signed-off-by: Robbie Harwood <rharwood@redhat.com>

grubby.8

@@ -148,7 +148,8 @@ the only items that can be updated is the kernel argument list, which is
 modified via the \fB-\-args\fR and \fB-\-remove-args\fR options. If the
 \fBALL\fR argument is used the variable \fB GRUB_CMDLINE_LINUX\fR in
 \fB/etc/default/grub\fR is updated with the latest kernel argument list,
-unless the \fB-\-no-etc-grub-update\fR option is used.
+unless the \fB-\-no-etc-grub-update\fR option is used or the file does not
+exist (e.g., on s390x).
 
 .TP
 \fB-\-zipl\fR

grubby.spec

@@ -1,6 +1,6 @@
 Name: grubby
 Version: 8.40
-Release: 57%{?dist}
+Release: 58%{?dist}
 Summary: Command line tool for updating bootloader configs
 License: GPLv2+
 URL: https://github.com/rhinstaller/grubby
@@ -131,6 +131,10 @@ current boot environment.
 %{_mandir}/man8/*.8*
 
 %changelog
+* Tue Jul 19 2022 Robbie Harwood <rharwood@redhat.com> - 8.40-58
+- Clarify that grub files aren't used on s390x in man page
+- Resolves: #2105118
+
 * Wed Jun 22 2022 Robbie Harwood <rharwood@redhat.com> - 8.40-57
 - Revert previous change (fedora sync)
 - Resolves: #1969362