The make substitution pattern was wrong. The source files are
"ostree.xml", not "ostree.1.xml", for instance.
Closes: #488
Approved by: cgwalters
man1_MANS = $(addprefix man/,$(man1_files))
man5_MANS = $(addprefix man/,$(man5_files))
-EXTRA_DIST += $(man1_MANS) $(man5_MANS) $(man1_MANS:=.xml) $(man5_MANS:=.xml)
+EXTRA_DIST += $(man1_MANS) $(man5_MANS) $(man1_MANS:.1=.xml) $(man5_MANS:.5=.xml)
XSLT_STYLESHEET = http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl