ctdb-scripts: Don't use the GNU awk gensub() function

ctdb-scripts: Don't use the GNU awk gensub() function

This is a gawk extension and can't be used reliably if just running
"awk".  It is simple enough to switch to using the standard sub() and
gsub() functions.

The alternative is to switch to explicitly running "gawk".  However,
although the eventscripts aren't exactly portable, it is probably
better to move closer to portability than further away.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Michael Adam <obnox@samba.org>