mesa: do not modify args when errors with GetProgramResourceName

Original purpose of these lines was to be more friendly against
GUI tools using the extension. However conformance suite explicitly
checks that buffers are not modified in error conditions.

Fixes:
   ES31-CTS.program_interface_query.buff-length

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Timothy Arceri <t_arceri@yahoo.com.au>

src/mesa/main/program_resource.c

@@ -274,12 +274,6 @@ _mesa_GetProgramResourceName(GLuint program, GLenum programInterface,
       _mesa_lookup_shader_program_err(ctx, program,
                                       "glGetProgramResourceName");
 
-   /* Set user friendly return values in case of errors. */
-   if (name)
-      *name = '\0';
-   if (length)
-      *length = 0;
-
    if (!shProg || !name)
       return;