Fix typo in SIGTTOU description.

Change-Id: Ie0db3e7df3e1f17b43f5645d027a90603139be2f
diff --git a/libc/include/sys/_sigdefs.h b/libc/include/sys/_sigdefs.h
index 6b47a03..eadf7b9 100644
--- a/libc/include/sys/_sigdefs.h
+++ b/libc/include/sys/_sigdefs.h
@@ -86,7 +86,7 @@
 __BIONIC_SIGDEF(STOP,19,"Stopped (signal)")
 __BIONIC_SIGDEF(TSTP,20,"Stopped")
 __BIONIC_SIGDEF(TTIN,21,"Stopped (tty input)")
-__BIONIC_SIGDEF(TTOU,22,"Stopper (tty output)")
+__BIONIC_SIGDEF(TTOU,22,"Stopped (tty output)")
 __BIONIC_SIGDEF(URG,23,"Urgent I/O condition")
 __BIONIC_SIGDEF(XCPU,24,"CPU time limit exceeded")
 __BIONIC_SIGDEF(XFSZ,25,"File size limit exceeded")