glsl: Drop crazy looping from no_matching_function_error().

glsl: Drop crazy looping from no_matching_function_error().

Since the built-in functions rewrite, num_builtins_to_link is always either
0 or 1, so we don't need tho crazy loop starting at -1 with a special
case.

All we need to do is print the prototypes from the current shader, and
the single built-in function shader (if present).

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>