smxo_appmenu.sh: Use 'which' to kill pre-existing instances

We may have 'sxmo_appmenu.sh' in the full commandline of other tools
which we don't want to kill, for example lisgd arguments.

Signed-off-by: Miles Alan <m@milesalan.com>

scripts/core/sxmo_appmenu.sh

@@ -266,7 +266,7 @@ mainloop() {
 	) & wait
 }
 
-pgrep -f sxmo_appmenu.sh  | grep -Ev "^${$}$" | xargs kill -TERM
+pgrep -f "$(which sxmo_appmenu.sh)" | grep -Ev "^${$}$" | xargs kill -TERM
 DMENUIDX=0
 PICKED=""
 ARGS="$*"