wrong syscall name in error message for #peeraddr

Without patch:

 % rm /tmp/u; ./ruby1.8 -r socket -e 's=UNIXServer.new("/tmp/u"); p s.peeraddr'
 -e:1:in `peeraddr': Socket is not connected - getsockname(2) (Errno::ENOTCONN)
                                                  ^^^^

With patch:

 % rm /tmp/u; ./ruby1.8  -I .ext/powerpc-darwin7.9.0  -r socket -e 's=UNIXServer.new("/tmp/u"); p s.peeraddr'
 -e:1:in `peeraddr': Socket is not connected - getpeername(2) (Errno::ENOTCONN)
                                                  ^^^^

Index: ext/socket/socket.c
===================================================================
--- ext/socket/socket.c (revision 11768)
+++ ext/socket/socket.c (working copy)
@@ -2233,7 +2233,7 @@
     GetOpenFile(sock, fptr);
 
     if (getpeername(fileno(fptr->f), (struct sockaddr*)&addr, &len) < 0)
-       rb_sys_fail("getsockname(2)");
+       rb_sys_fail("getpeername(2)");
     return unixaddr(&addr, len);
 }
 #endif