ROMCC: fix unused attribute lookup

commit 57cd1dd29679918afa650c2a7e82a474765f357d added this attribute,
but with wrong length, so it actually never matched.

Change-Id: Ibcc7816b5fa895faa66710cc29de38f129be6a2b
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-on: http://review.coreboot.org/1133
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Tested-by: build bot (Jenkins)
Reviewed-by: Mathias Krause <minipli@googlemail.com>
diff --git a/util/romcc/romcc.c b/util/romcc/romcc.c
index b0f6198..15e950c 100644
--- a/util/romcc/romcc.c
+++ b/util/romcc/romcc.c
@@ -24992,7 +24992,7 @@
 	state.i_noinline      = lookup(&state, "noinline", 8);
 	state.i_always_inline = lookup(&state, "always_inline", 13);
 	state.i_noreturn      = lookup(&state, "noreturn", 8);
-	state.i_unused        = lookup(&state, "unused", 8);
+	state.i_unused        = lookup(&state, "unused", 6);
 
 	/* Process the command line macros */
 	process_cmdline_macros(&state);