open-ocd: use spec deps

Formula/open-ocd.rb

@@ -4,7 +4,13 @@ class OpenOcd < Formula
   homepage 'http://sourceforge.net/projects/openocd/'
   url 'http://downloads.sourceforge.net/project/openocd/openocd/0.7.0/openocd-0.7.0.tar.bz2'
   sha1 '40fa518af4fae273f24478249fc03aa6fcce9176'
-  head 'git://git.code.sf.net/p/openocd/code'
+
+  head do
+    url 'git://git.code.sf.net/p/openocd/code'
+
+    depends_on :libtool
+    depends_on :automake
+  end
 
   option 'enable-ft2232_libftdi', 'Enable building support for FT2232 based devices with libftdi driver'
   option 'enable-ft2232_ftd2xx',  'Enable building support for FT2232 based devices with FTD2XX driver'
@@ -12,11 +18,6 @@ class OpenOcd < Formula
   depends_on 'libusb-compat'
   depends_on 'libftdi0' if build.include? 'enable-ft2232_libftdi'
 
-  if build.head?
-    depends_on :libtool
-    depends_on :automake
-  end
-
   def install
     args = %W[
       --disable-dependency-tracking