docs: ensure outputfile is deleted if rst2html/rst2man fail

This avoids leaving a zero length or partially generated output
file on errors.
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

docs/Makefile.am

@@ -262,21 +262,21 @@ man8_MANS = $(manpages8_rst:%.rst=%.8)
 	   grep -v '^\.\. contents::' < $< | \
 	   sed -e 's|SYSCONFDIR|$(sysconfdir)|g' \
 	       -e 's|RUNSTATEDIR|$(runstatedir)|g' | \
-	   $(RST2MAN) > $@
+	   $(RST2MAN) > $@ || { rm $@ && exit 1; }
 
 %.7: %.rst
 	$(AM_V_GEN)$(MKDIR_P) `dirname $@` && \
 	   grep -v '^\.\. contents::' < $< | \
 	   sed -e 's|SYSCONFDIR|$(sysconfdir)|g' \
 	       -e 's|RUNSTATEDIR|$(runstatedir)|g' | \
-	   $(RST2MAN) > $@
+	   $(RST2MAN) > $@ || { rm $@ && exit 1; }
 
 %.8: %.rst
 	$(AM_V_GEN)$(MKDIR_P) `dirname $@` && \
 	   grep -v '^\.\. contents::' < $< | \
 	   sed -e 's|SYSCONFDIR|$(sysconfdir)|g' \
 	       -e 's|RUNSTATEDIR|$(runstatedir)|g' | \
-	   $(RST2MAN) > $@
+	   $(RST2MAN) > $@ || { rm $@ && exit 1; }
 
 manpages/virkeycode-%.rst: $(top_srcdir)/src/keycodemapdb/data/keymaps.csv \
 		$(top_srcdir)/src/keycodemapdb/tools/keymap-gen Makefile.am
@@ -415,11 +415,11 @@ manpages/%.html.in: manpages/%.rst
 	 grep -v '^:Manual ' < $< | \
 	  sed -e 's|SYSCONFDIR|$(sysconfdir)|g' \
 	     -e 's|RUNSTATEDIR|$(runstatedir)|g' | \
-	  $(RST2HTML) > $@
+	  $(RST2HTML) > $@ || { rm $@ && exit 1; }
 
 %.html.in: %.rst
 	$(AM_V_GEN)$(MKDIR_P) `dirname $@` && \
-	  $(RST2HTML) $< > $@
+	  $(RST2HTML) $< > $@ || { rm $@ && exit 1; }
 
 %.html.tmp: %.html.in site.xsl subsite.xsl page.xsl \
 		$(acl_generated)