platform/x86: ideapad-laptop: Use __func__ instead of write_ec_cmd in pr_err

Address the following  checkpatch warning by using __func__ instead:
WARNING: Prefer using '"%s...", __func__' to using 'write_ec_cmd',
this function's name, in a string
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

drivers/platform/x86/ideapad-laptop.c

@@ -231,7 +231,7 @@ static int write_ec_cmd(acpi_handle handle, int cmd, unsigned long data)
 		if (val == 0)
 			return 0;
 	}
-	pr_err("timeout in write_ec_cmd\n");
+	pr_err("timeout in %s\n", __func__);
 	return -1;
 }