exposay: don't try to activate if esurface is NULL

Fix logic so view can't be NULL deref'd... that is, previously
if 'esurface' was NULL, then 'view' remained NULL and we
attempted to deref 'view' unconditionally.  Instead, if
'esurface' is NULL then we can't get the view so just return
immediately.

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>
input-panel: validate return value of get_default_view

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>