Gcc thinks base could be used uninitialized, so shut it up

Bug from r3791.

Corresponding to flashrom svn r357 and coreboot v2 svn r3792.
Signed-off-by: Peter Stuge <peter@stuge.se>
Acked-by: Peter Stuge <peter@stuge.se>

flashrom.c

@@ -105,7 +105,7 @@ struct flashchip *probe_flash(struct flashchip *first_flash, int force)
 {
 	volatile uint8_t *bios;
 	struct flashchip *flash;
-	unsigned long base, size;
+	unsigned long base = 0, size;
 
 	for (flash = first_flash; flash && flash->name; flash++) {
 		if (chip_to_probe && strcmp(flash->name, chip_to_probe) != 0)