kernel-doc parser mishandles declarations split into lines

kernel-doc parser mishandles declarations split into lines

Reported by Johannes Berg [1].  Problem here: function
process_proto_type() concatenates the striped lines of declaration
without any whitespace. A one-liner of::

 struct something {
       struct foo
       bar;
       };

has to be::

 struct something {struct foo bar;};

Without the patching process_proto_type(), the result missed the space
between 'foo' and 'bar'::

 struct something {struct foobar;};

Bugfix of process_proto_type() brings next error when blank lines
between enum declaration::

 warning: Enum value ' ' not described in enum 'foo'

Problem here: dump_enum() does not strip leading whitespaces from
the concatenated string (with the new additional space from
process_proto_type).

[1] https://www.mail-archive.com/linux-doc@vger.kernel.org/msg12410.html

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>