scripts/gdb: decode bytestream on dmesg for Python3

The recent fixes to lx-dmesg, now allow the command to print
successfully on Python3, however the python interpreter wraps the bytes
for each line with a b'<text>' marker.

To remove this, we need to decode the line, where .decode() will default
to 'UTF-8'

Link: http://lkml.kernel.org/r/d67ccf93f2479c94cb3399262b9b796e0dbefcf2.1462865983.git.jan.kiszka@siemens.com
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Acked-by: Dom Cote <buzdelabuz2@gmail.com>
Tested-by: Dom Cote <buzdelabuz2@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/gdb/linux/dmesg.py

@@ -51,10 +51,10 @@ class LxDmesg(gdb.Command):
                 continue
 
             text_len = utils.read_u16(log_buf[pos + 10:pos + 12])
-            text = log_buf[pos + 16:pos + 16 + text_len]
+            text = log_buf[pos + 16:pos + 16 + text_len].decode()
             time_stamp = utils.read_u64(log_buf[pos:pos + 8])
 
-            for line in memoryview(text).tobytes().splitlines():
+            for line in text.splitlines():
                 gdb.write("[{time:12.6f}] {line}\n".format(
                     time=time_stamp / 1000000000.0,
                     line=line))