qapi: Fix C identifiers generated for names containing '.'
c_fun() maps '.' to '_', c_var() doesn't. Nothing prevents '.' in
QAPI names that get passed to c_var().
Which QAPI names get passed to c_fun(), to c_var(), or to both is not
obvious. Names of command parameters and struct type members get
passed to c_var().
c_var() strips a leading '*', but this cannot happen. c_fun()
doesn't.
Fix c_var() to work exactly like c_fun().
Perhaps they should be replaced by a single mapping function.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
[add 'import string'] Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com>