Added explicit 'void' to function that takes no argument

This is the correct way to tell that a function takes no
arguments, because an empty parameter list tells the compiler
that it is not yet defined, and is tolerated only for
compatibility with very old C compilers for whom prototypes
were not yet a defined language element.

src/defaults.c

@@ -753,7 +753,7 @@ WDefaultEntry optionList[] = {
 	    &wPreferences.cycle_ignore_minimized, getBool, NULL, NULL, NULL}
 };
 
-static void initDefaults()
+static void initDefaults(void)
 {
 	unsigned int i;
 	WDefaultEntry *entry;

src/keybind.h

@@ -122,6 +122,6 @@ typedef struct WShortKey {
     KeyCode keycode;
 } WShortKey;
 
-void wKeyboardInitialize();
+void wKeyboardInitialize(void);
 
 #endif /* WMKEYBIND_H */

src/moveres.c

@@ -535,7 +535,7 @@ static void drawFrames(WWindow * wwin, WMArray * array, int dx, int dy)
 	}
 }
 
-static void flushMotion()
+static void flushMotion(void)
 {
 	XEvent ev;
 

src/winspector.h

@@ -30,7 +30,7 @@ void wHideInspectorForWindow(WWindow *wwin);
 
 void wUnhideInspectorForWindow(WWindow *wwin);
 
-void wDestroyInspectorPanels();
+void wDestroyInspectorPanels(void);
 
 WWindow *wGetWindowOfInspectorForWindow(WWindow *wwin);