display the error to the user if volume stop is given on a volume which does not exist
display the error to the user if volume stop is given on a volume which does not exist

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

BUG: 2140 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2140

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster