x32: fix decoding of i386 personality lseek syscall

On x32, tcp->ext_arg is not initialized for i386 personality,
so tcp->u_arg has to be used instead.

* lseek.c (SYS_FUNC(lseek)) [X32]: Handle "current_personality == 1" case.
diff --git a/lseek.c b/lseek.c
index f02158e..8d8f21b 100644
--- a/lseek.c
+++ b/lseek.c
@@ -16,6 +16,12 @@
 	int whence;
 
 	printfd(tcp, tcp->u_arg[0]);
+# ifdef X32
+	/* tcp->ext_arg is not initialized for i386 personality */
+	if (current_personality == 1)
+		offset = tcp->u_arg[1];
+	else
+# endif
 	offset = tcp->ext_arg[1];
 	whence = tcp->u_arg[2];
 	if (whence == SEEK_SET)