bletiny: Fix parse uuid cmd argument
bletiny: Fix parse uuid cmd argument

parse_arg_uint16 extracted UUID argument and if it failed to parse it
parse_arg_byte_stream_exact_length was called, but coudldn't find uuid
argument. Additionally the part that parsed UUID in
"e7add801-b042-4876-aae1112855353cc1" format was ineffective, because
parse_arg_byte_stream_exact_length expects arg name as a first
parameter. Finally parsed stream needed to be reversed.

With this patch it is possible to pass Read Using Characteristic UUID
tests (TC_GAR_CL_BV_03_C, etc.)

mlaz/mynewt-core,IMGJulian/incubator-mynewt-core,IMGJulian/incubator-mynewt-core,mlaz/mynewt-core,IMGJulian/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,wes3/incubator-mynewt-core,mlaz/mynewt-core,andrzej-kaczmarek/apache-mynewt-core,andrzej-kaczmarek/apache-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core,wes3/incubator-mynewt-core,wes3/incubator-mynewt-core,mlaz/mynewt-core,andrzej-kaczmarek/apache-mynewt-core,IMGJulian/incubator-mynewt-core,wes3/incubator-mynewt-core,andrzej-kaczmarek/apache-mynewt-core,mlaz/mynewt-core,wes3/incubator-mynewt-core,IMGJulian/incubator-mynewt-core,andrzej-kaczmarek/incubator-mynewt-core