booster: Fix fd leak due to incorrect NULL check
booster: Fix fd leak due to incorrect NULL check

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 174 (booster: fd_ts, they are a leakin)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=174

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster