Prior to this commit, the command "scripts/objdiff record path/to/*.o"
disassembled the given object into ".tmp_objdiff/path/to/*.o" file.

The problem here is that recorded disassemblies are lost if we run
"make clean" because it removes all the *.o files.
Disassembled code should be dumped into *.dis instead of *.o files.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NMichal Marek <mmarek@suse.cz>