efi/libstub: Use C99-style for loop to traverse handle buffer

Tweak the for_each_efi_handle() macro in order to avoid the need on the
part of the caller to provide a loop counter variable.

Also move efi_get_handle_num() to the callers, so that each occurrence
can be replaced with the actual number returned by the simplified
LocateHandleBuffer API.

Signed-off-by: Ard Biesheuvel <[e-mail]>

drivers/firmware/efi/libstub/efistub.h

···
 #define efi_get_handle_num(size)					\
 	((size) / (efi_is_native() ? sizeof(efi_handle_t) : sizeof(u32)))
 
-#define for_each_efi_handle(handle, array, size, i)			\
-	for (i = 0;							\
-	     i < efi_get_handle_num(size) &&				\
-		((handle = efi_get_handle_at((array), i)) || true);	\
-	     i++)
+#define for_each_efi_handle(handle, array, num)				\
+	for (int __i = 0; __i < (num) &&				\
+		((handle = efi_get_handle_at((array), __i)) || true);	\
+	     __i++)
 
 static inline
 void efi_set_u64_split(u64 data, u32 *lo, u32 *hi)

drivers/firmware/efi/libstub/gop.c

···
 {
 	efi_graphics_output_protocol_t *first_gop;
 	efi_handle_t h;
-	int i;
 
 	first_gop = NULL;
 
-	for_each_efi_handle(h, handles, size, i) {
+	for_each_efi_handle(h, handles, efi_get_handle_num(size)) {
 		efi_status_t status;
 
 		efi_graphics_output_protocol_t *gop;

drivers/firmware/efi/libstub/pci.c

···
 	efi_handle_t handle;
 	efi_status_t status;
 	u16 class, command;
-	int i;
 
 	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto,
 			     NULL, &pci_handle_size, NULL);
···
 		goto free_handle;
 	}
 
-	for_each_efi_handle(handle, pci_handle, pci_handle_size, i) {
+	for_each_efi_handle(handle, pci_handle, efi_get_handle_num(pci_handle_size)) {
 		efi_pci_io_protocol_t *pci;
 		unsigned long segment_nr, bus_nr, device_nr, func_nr;
 
···
 		efi_bs_call(disconnect_controller, handle, NULL, NULL);
 	}
 
-	for_each_efi_handle(handle, pci_handle, pci_handle_size, i) {
+	for_each_efi_handle(handle, pci_handle, efi_get_handle_num(pci_handle_size)) {
 		efi_pci_io_protocol_t *pci;
 
 		status = efi_bs_call(handle_protocol, handle, &pci_proto,

drivers/firmware/efi/libstub/x86-stub.c

···
 	unsigned long size = 0;
 	struct setup_data *data;
 	efi_handle_t h;
-	int i;
 
 	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 			     &pci_proto, NULL, &size, pci_handle);
···
 	while (data && data->next)
 		data = (struct setup_data *)(unsigned long)data->next;
 
-	for_each_efi_handle(h, pci_handle, size, i) {
+	for_each_efi_handle(h, pci_handle, efi_get_handle_num(size)) {
 		efi_pci_io_protocol_t *pci = NULL;
 		struct pci_setup_rom *rom;