refactor(uncrustify): change rules to better align with the style guide

Add space around arithmetic operators '+' and '-'.
Remove space between back-to-back parentheses, i.e. ')(' vs. ') ('.
Remove space between '((' or '))' of control statements.
Add space between ')' and '{' of control statements.
Remove space between function name and '(' on function declaration.
Collapse empty blocks between '{' and '}'.
Remove newline at the end of the file.
Remove newline between 'enum' and '{'.
Remove newline between '}' and ')' in a function invocation.
Remove newline between '}' and 'while' of 'do' statement.

src/nvim/rbuffer.c

@@ -224,4 +224,3 @@ int rbuffer_cmp(RBuffer *buf, const char *str, size_t count)
 
   return memcmp(str + n, buf->start_ptr, count);
 }
-