fw_cfg: remove useless casts

This patch is the result of coccinelle script
scripts/coccinelle/typecast.cocci

CC: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 6a68e59..1776b1b 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -180,7 +180,7 @@
         temp = qemu_opt_get(opts, "splash-time");
         if (temp != NULL) {
             p = (char *)temp;
-            boot_splash_time = strtol(p, (char **)&p, 10);
+            boot_splash_time = strtol(p, &p, 10);
         }
     }
 
@@ -240,7 +240,7 @@
         temp = qemu_opt_get(opts, "reboot-timeout");
         if (temp != NULL) {
             p = (char *)temp;
-            reboot_timeout = strtol(p, (char **)&p, 10);
+            reboot_timeout = strtol(p, &p, 10);
         }
     }
     /* validate the input */