Some systems (FreeBSD, in particular) don't define the RM macro in automake


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@189 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/configure.ac b/configure.ac
index 382b228..b8f6179 100644
--- a/configure.ac
+++ b/configure.ac
@@ -173,6 +173,7 @@
 AC_SUBST(RPMARCH)
 AC_SUBST(DEBARCH)
 AC_SUBST(BUILD)
+AC_SUBST(RM)
 
 # jconfig.h is the file we use, but we have another before that to
 # fool autoheader. the reason is that we include this header in our