or1k: fix printing of invalid 1st argument of or1k_atomic syscall

* or1k_atomic.c (SYS_FUNC(or1k_atomic)): Print 1st argument using
printxval_long.
diff --git a/or1k_atomic.c b/or1k_atomic.c
index a5755c6..54d3a0d 100644
--- a/or1k_atomic.c
+++ b/or1k_atomic.c
@@ -44,7 +44,7 @@
 
 SYS_FUNC(or1k_atomic)
 {
-	printxval(atomic_ops, tcp->u_arg[0], "???");
+	printxval_long(atomic_ops, tcp->u_arg[0], "???");
 	switch(tcp->u_arg[0]) {
 	case OR1K_ATOMIC_SWAP:
 		tprintf(", 0x%lx, 0x%lx", tcp->u_arg[1], tcp->u_arg[2]);