[syslinux:firmware] txt: always rebuild necessary directories

[syslinux-bot for Matt Fleming]

Commit-ID:  97bff28959e9deed6b78dd7df974797476683006
Gitweb:     http://www.syslinux.org/commit/97bff28959e9deed6b78dd7df974797476683006
Author:     Matt Fleming <matt.fleming at intel.com>
AuthorDate: Tue, 11 Jun 2013 16:24:50 +0100
Committer:  Matt Fleming <matt.fleming at intel.com>
CommitDate: Mon, 17 Jun 2013 10:49:15 +0100

txt: always rebuild necessary directories

Even if they're found in VPATH. This change ensures that txt/html is
ignored in the source directory and that $(OBJ)/txt/html is always
created in the output directory, avoiding the following error,

asciidoc: FAILED: syslinux.txt: line 8: unexpected error:
asciidoc: ------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/bin/asciidoc", line 6016, in asciidoc
    writer.open(outfile, reader.bom)
  File "/usr/bin/asciidoc", line 4430, in open
    self.f = open(fname,'wb+')
IOError: [Errno 2] No such file or directory: '/syslinux.git/efi64/txt/html/syslinux.html'

Signed-off-by: Matt Fleming <matt.fleming at intel.com>

---
 txt/Makefile | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/txt/Makefile b/txt/Makefile
index 0e4cfb4..2c75ab8 100644
--- a/txt/Makefile
+++ b/txt/Makefile
@@ -71,8 +71,11 @@ syslinux.cfg.txt:	com-bug.txt com-rpt.txt
 # %.html:	%.txt
 # 	asciidoc -D html $<
 
+# Mark as .PHONY so they're ignored if found in VPATH
+.PHONY: html/ man/ text/ xhtml/
+
 html/ man/ text/ xhtml/:
-	mkdir $@
+	mkdir -p $@
 
 html/%.html:	%.txt html/
 	asciidoc -o $@ $<