Frame Relay: make the buffer big enough for the biggest message.

(cherry picked from commit df2dc59f6c0bf217afdbddbd178d3114a9edc2b5)
diff --git a/print-fr.c b/print-fr.c
index 70b4d0a..f0d7fbe 100644
--- a/print-fr.c
+++ b/print-fr.c
@@ -147,7 +147,7 @@
 
     static u_int dlci, addr_len;
     static uint32_t flags;
-    static char buffer[sizeof("DLCI xxxxxxxxxx")];
+    static char buffer[sizeof("parse_q922_header() returned XXXXXXXXXXX")];
     int ret;
     memset(buffer, 0, sizeof(buffer));