tcg: fix typo in readme

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/tcg/README b/tcg/README
index a2b69dd..a18a87f 100644
--- a/tcg/README
+++ b/tcg/README
@@ -364,7 +364,7 @@
 
 ********* QEMU specific operations
 
-* tb_exit t0
+* exit_tb t0
 
 Exit the current TB and return the value t0 (word type).