shell: Fix inverted test for locked in workspace bindings
diff --git a/src/shell.c b/src/shell.c
index 613ce65..90db992 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -3258,7 +3258,7 @@
 	struct desktop_shell *shell = data;
 	unsigned int new_index = shell->workspaces.current;
 
-	if (!shell->locked)
+	if (shell->locked)
 		return;
 	if (new_index != 0)
 		new_index--;
@@ -3273,7 +3273,7 @@
 	struct desktop_shell *shell = data;
 	unsigned int new_index = shell->workspaces.current;
 
-	if (!shell->locked)
+	if (shell->locked)
 		return;
 	if (new_index < shell->workspaces.num - 1)
 		new_index++;
@@ -3288,7 +3288,7 @@
 	struct desktop_shell *shell = data;
 	unsigned int new_index;
 
-	if (!shell->locked)
+	if (shell->locked)
 		return;
 	new_index = key - KEY_F1;
 	if (new_index >= shell->workspaces.num)