flash/nor/faux.c: fixing check for failed malloc

Error found by static code analysis using the semantic pattern
null_ref2/mini_null_ref2.cocci, see coccinellery.org

Change-Id: Ic817c29f0ccf2b41fc8f7d9a480ad30d6e5b7ab8
Signed-off-by: Alexander Kurz <akurz@blala.de>
Reviewed-on: http://openocd.zylin.com/3364
Tested-by: jenkins
Reviewed-by: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

src/flash/nor/faux.c

@@ -50,7 +50,7 @@ FLASH_BANK_COMMAND_HANDLER(faux_flash_bank_command)
 		return ERROR_FAIL;
 	}
 	info->memory = malloc(bank->size);
-	if (info == NULL) {
+	if (info->memory == NULL) {
 		free(info);
 		LOG_ERROR("no memory for flash bank info");
 		return ERROR_FAIL;