modpost: fix ishtp MODULE_DEVICE_TABLE built on big-endian host

When MODULE_DEVICE_TABLE(ishtp, ) is built on a host with a different
endianness from the target architecture, it results in an incorrect
MODULE_ALIAS().

For example, see a case where drivers/platform/x86/intel/ishtp_eclite.c
is built as a module for x86.

If you build it on a little-endian host, you will get the correct
MODULE_ALIAS:

    $ grep MODULE_ALIAS drivers/platform/x86/intel/ishtp_eclite.mod.c
    MODULE_ALIAS("ishtp:{6A19CC4B-D760-4DE3-B14D-F25EBD0FBCD9}");

However, if you build it on a big-endian host, you will get a wrong
MODULE_ALIAS:

    $ grep MODULE_ALIAS drivers/platform/x86/intel/ishtp_eclite.mod.c
    MODULE_ALIAS("ishtp:{BD0FBCD9-F25E-B14D-4DE3-D7606A19CC4B}");

This issue has been unnoticed because the x86 kernel is most likely built
natively on an x86 host.

The guid field must not be reversed because guid_t is an array of __u8.

Fixes: fa443bc ("HID: intel-ish-hid: add support for MODULE_DEVICE_TABLE()")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Author: masahir0y

scripts/mod/file2alias.c

@@ -1401,10 +1401,10 @@ static int do_mhi_ep_entry(const char *filename, void *symval, char *alias)
 /* Looks like: ishtp:{guid} */
 static int do_ishtp_entry(const char *filename, void *symval, char *alias)
 {
-	DEF_FIELD(symval, ishtp_device_id, guid);
+	DEF_FIELD_ADDR(symval, ishtp_device_id, guid);
 
 	strcpy(alias, ISHTP_MODULE_PREFIX "{");
-	add_guid(alias, guid);
+	add_guid(alias, *guid);
 	strcat(alias, "}");
 
 	return 1;