Makefiles: Updated Makefiles to use db2x_docbook2man when docbook2x-man is not installed

- db2x_docbook2man is what Fedora contains

Makefile.modules

@@ -295,7 +295,7 @@ endif
 ifneq (,$(wildcard $(MOD_NAME).xml))
 
 $(MOD_NAME).7: $(MOD_NAME).xml
-	docbook2x-man -s ../../doc/stylesheets/serdoc2man.xsl $<
+	$(DOCBOOK) -s ../../doc/stylesheets/serdoc2man.xsl $<
 
 man: $(MOD_NAME).7
 

Makefile.shared

@@ -42,3 +42,8 @@ sh_err_fail=
 try_err=$(1) ; if [ $$? != 0 ]; then echo ERROR: $(1) failed ; fi
 endif
 
+DOCBOOK = $(shell which docbook2x-man 2>/dev/null)
+ifeq ($(DOCBOOK),)
+	DOCBOOK = $(shell which db2x_docbook2man 2>/dev/null)
+endif
+

Makefile.utils

@@ -123,7 +123,7 @@ endif
 ifneq (,$(wildcard $(UTIL_NAME).xml))
 
 $(UTIL_NAME).7: $(UTIL_NAME).xml
-	docbook2x-man -s ../../doc/stylesheets/serdoc2man.xsl $<
+	$(DOCBOOK) -s ../../doc/stylesheets/serdoc2man.xsl $<
 
 man: $(UTIL_NAME).7