Fix 0012373: log_event doesn't log simple strings

$s_msg doesn't get a value if $p_msg is an array. When $s_msg is used
later on in the function it will be undefined, throwing an error.

This is solved by giving $s_msg a value when $p_msg is an array.

Signed-off-by: David Hicks hickseydr@optusnet.com.au