[yelp-tools] yelp.m4: Avoid argument list too long error when cleaning

[Shaun McCance <shaunm src gnome org>]

commit a3a80d6cfd90fcf5dedbf3221d647677fc50261e
Author: Dan Nicholson <nicholson endlessm com>
Date:   Sun Feb 6 21:44:57 2022 -0500

    yelp.m4: Avoid argument list too long error when cleaning
    
    https://gitlab.gnome.org/GNOME/yelp-tools/-/merge_requests/5

 tools/yelp.m4 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/tools/yelp.m4 b/tools/yelp.m4
index 3a882292..88b27a14 100644
--- a/tools/yelp.m4
+++ b/tools/yelp.m4
@@ -110,7 +110,9 @@ $(_HELP_LC_STAMPS): $(_HELP_C_FILES) $(_HELP_C_EXTRA)
 .PHONY: clean-help
 mostlyclean-am: $(if $(HELP_ID),clean-help)
 clean-help:
-       rm -f $(_HELP_LC_FILES) $(_HELP_LC_STAMPS) $(_HELP_MOFILES)
+       $(file >clean-help-files,$(_HELP_LC_FILES) $(_HELP_LC_STAMPS) $(_HELP_MOFILES))
+       @xargs -t rm -f < clean-help-files
+       rm -f clean-help-files
 
 EXTRA_DIST ?=
 EXTRA_DIST += $(_HELP_C_EXTRA) $(_HELP_C_MEDIA)