kernel-module-split.bbclass: Fix modinfo decoding in old kernels

Before linux commit d36b691077dc59c74efec0d54ed21b86f7a2a21a, some
strings contained invalid utf-8 character which made
split_kernel_module_packages unhappy when parsing ums-isd200.ko:

Exception: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf6 in position 21: invalid start byte

(From OE-Core rev: 503b977acf6984120818cbc5cfd35ff2cffb39cd)

Signed-off-by: Pau Espin Pedrol <pespin@sysmocom.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/kernel-module-split.bbclass

@@ -48,7 +48,8 @@ python split_kernel_module_packages () {
         tmpfile = tf[1]
         cmd = "%sobjcopy -j .modinfo -O binary %s %s" % (d.getVar("HOST_PREFIX") or "", file, tmpfile)
         subprocess.check_call(cmd, shell=True)
-        f = open(tmpfile)
+        # errors='replace': Some old kernel versions contain invalid utf-8 characters in mod descriptions (like 0xf6, 'ö')
+        f = open(tmpfile, errors='replace')
         l = f.read().split("\000")
         f.close()
         os.close(tf[0])