Fix a typo: the macro is currently called %{buildsubdir}

--- ./build/files.c.orig	2005-12-14 19:22:43.000000000 +0000
+++ ./build/files.c	2006-02-17 13:57:25.000000000 +0000
@@ -1942,7 +1954,7 @@ static int processPackageFiles(Spec spec
 	if (*pkg->fileFile == '/') {
 	    ffn = rpmGetPath(pkg->fileFile, NULL);
 	} else {
-	    /* XXX FIXME: add %{_buildsubdir} */
+	    /* XXX FIXME: add %{buildsubdir} */
 	    ffn = rpmGetPath("%{_builddir}/",
 		(spec->buildSubdir ? spec->buildSubdir : "") ,
 		"/", pkg->fileFile, NULL);
--- ./build/pack.c.orig	2005-07-15 15:06:57.000000000 +0000
+++ ./build/pack.c	2005-12-18 15:14:56.000000000 +0000
@@ -138,7 +138,7 @@ static /*@only@*/ /*@null@*/ StringBuf a
     FILE * f;
     FD_t fd;
 
-    fn = rpmGetPath("%{_builddir}/%{?_buildsubdir:%{_buildsubdir}/}", file, NULL);
+    fn = rpmGetPath("%{_builddir}/%{?buildsubdir:%{buildsubdir}/}", file, NULL);
 
     fd = Fopen(fn, "r.ufdio");
     if (fn != buf) fn = _free(fn);