vty: Fix misusage of snprintf in vty/utils.c
Compiled with ubuntu 1204 (precise), where -Wformat-security is enabled by
-Wall.
Test yields ok, but the current implementation doesn't properly support
multi-character separators and end strings. So the test output is truncated.
Addresses:
utils.c: In function 'vty_cmd_string_from_valstr':
utils.c:84:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:84:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:108:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:108:2: warning: format not a string literal and no format arguments [-Wformat-security]
6 files changed