rom.sh: don't dry-run mkcoreboottar

same as the last change. make the main function a wrapper
that dry-runs the real function.

if the "dry" variable is blank, it executes.

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/rom.sh

@@ -180,6 +180,11 @@ cprom()
 }
 
 mkcoreboottar()
+{
+	$dry realmkcoreboottar
+}
+
+realmkcoreboottar()
 {
 	[ "$target" = "$tree" ] && return 0; [ "$XBMK_RELEASE" = "y" ] && \
 	    [ "$release" != "n" ] && $dry mkrom_tarball "bin/$target"; return 0