linker: Use helper variable sh

This looks like a copy-and-paste left over.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 70f3d5b..63548e0 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -885,8 +885,8 @@
    for (unsigned i = 0; i < num_shaders; i++) {
       struct gl_shader *sh = shader_list[i];
 
-      for (unsigned j = 0; j < shader_list[i]->NumUniformBlocks; j++) {
-	 link_assign_uniform_block_offsets(shader_list[i]);
+      for (unsigned j = 0; j < sh->NumUniformBlocks; j++) {
+	 link_assign_uniform_block_offsets(sh);
 
 	 int index = link_cross_validate_uniform_block(mem_ctx,
 						       &uniform_blocks,