Addressed void* return warning in all keymaps

keyboard/atomic/atomic.c

@@ -1,16 +1,16 @@
 #include "atomic.h"
 
 __attribute__ ((weak))
-void * matrix_init_user(void) {
+void matrix_init_user(void) {
 	// leave these blank
-};
+}
 
 __attribute__ ((weak))
-void * matrix_scan_user(void) {
+void matrix_scan_user(void) {
 	// leave these blank
-};
+}
 
-void * matrix_init_kb(void) {
+void matrix_init_kb(void) {
 	// put your keyboard start-up code here
 	// runs once when the firmware starts up
 
@@ -25,16 +25,12 @@ void * matrix_init_kb(void) {
     DDRE |= (1<<6);
     PORTE |= (1<<6);
 
-	if (matrix_init_user) {
-		(*matrix_init_user)();
-	}
-};
+	matrix_init_user();
+}
 
-void * matrix_scan_kb(void) {
+void matrix_scan_kb(void) {
 	// put your looping keyboard code here
 	// runs every cycle (a lot)
 
-	if (matrix_scan_user) {
-		(*matrix_scan_user)();
-	}
-};
+	matrix_scan_user();
+}