Linux 2.6.13-rc6

Last (?) -rc, partly brought on by the aic7xxx performance fixes (ie get
them tested in an -rc release before the real 2.6.13).
diff --git a/Makefile b/Makefile
index 0196b20..2c14861 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 2
 PATCHLEVEL = 6
 SUBLEVEL = 13
-EXTRAVERSION =-rc5
+EXTRAVERSION =-rc6
 NAME=Woozy Numbat
 
 # *DOCUMENTATION*