grep -m is not available on BSD, so use head -1 instead

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@47444 65c4cc65-6c06-0410-ace0-fbb531ad65f3

build_tools/prep_moduledeps

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 get_description() {
-	TDESC=`grep -m 1 -e AST_MODULE_INFO ${1} | cut -d '"' -f 2`
+	TDESC=`grep -e AST_MODULE_INFO ${1} | head -n 1 | cut -d '"' -f 2`
 }
 
 process_dir() {