remove a few unused constant for size of buffers

As pointed by gcc, a few constants which contain sizes for buffers are not
used anywhere in the code. This is probably due to code cleanup, where
these buffers have been removed or where size is automatically calculated
by using 'sizeof' instead to reduce risk of bugs.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

WPrefs.app/Menu.c

@@ -42,7 +42,6 @@ typedef enum {
 } InfoType;
 
 #define MAX_SECTION_SIZE 4
-#define PATH_LEN 256
 
 typedef struct _Panel {
 	WMBox *box;