checkpolicy: use strict function prototype for definitions

Clang 15 starts to complain about non strict function definitions:

    policy_define.c:4907:30: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
    int define_devicetree_context()
                                 ^
                                  void
    policy_define.c:5298:29: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
    int define_ipv4_node_context()
                                ^
                                 void

Signed-off-by: Christian Göttsche <[email protected]>
Reviewed-by: Daniel Burgener <[email protected]>
Acked-by: James Carter <[email protected]>

Author: cgzones

checkpolicy/policy_define.c

@@ -4904,7 +4904,7 @@ int define_pcidevice_context(unsigned long device)
 	return -1;
 }
 
-int define_devicetree_context()
+int define_devicetree_context(void)
 {
 	ocontext_t *newc, *c, *l, *head;
 
@@ -5295,7 +5295,7 @@ int define_netif_context(void)
 	return 0;
 }
 
-int define_ipv4_node_context()
+int define_ipv4_node_context(void)
 {	
 	char *id;
 	int rc = 0;