ivi-shell: Fix incorrect use of logical instead of bitwise operator

Fix the code to use the correct bitwise AND operator '&', instead of the
currently used logical AND operator '&&', to check the value of a bit
flag in a bit mask.

This problem was reported as a warning when building with clang.

Reviewed-by: Emre Ucan <eucan@de.adit-jv.com>
diff --git a/ivi-shell/ivi-layout.c b/ivi-shell/ivi-layout.c
index 87adde3..394179b 100644
--- a/ivi-shell/ivi-layout.c
+++ b/ivi-shell/ivi-layout.c
@@ -617,7 +617,7 @@
 			* the weston_view below this ivi_view. Otherwise content
 			* of this ivi_view will stay visible.
 			*/
-			if ((ivilayer->prop.event_mask | ivisurf->prop.event_mask) &&
+			if ((ivilayer->prop.event_mask | ivisurf->prop.event_mask) &
 			    IVI_NOTIFICATION_VISIBILITY)
 				weston_view_damage_below(ivi_view->view);