renderer: fix some minor sparse warnings

src/virglrenderer.c

@@ -43,7 +43,7 @@
 #include "virglrenderer.h"
 #include "virgl_egl.h"
 
-struct virgl_egl *egl_info;
+static struct virgl_egl *egl_info;
 /* new API - just wrap internal API for now */
 
 int virgl_renderer_resource_create(struct virgl_renderer_resource_create_args *args, struct iovec *iov, uint32_t num_iovs)

src/vrend_blitter.c

@@ -540,7 +540,7 @@ void vrend_renderer_blit_gl(struct vrend_context *ctx,
     
     glUniform1i(samp_loc, 0);
 
-    glVertexAttribPointer(pos_loc, 4, GL_FLOAT, GL_FALSE, 8 * sizeof(float), 0);
+    glVertexAttribPointer(pos_loc, 4, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)0);
     glVertexAttribPointer(tc_loc, 4, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void *)(4 * sizeof(float)));
     
     glEnableVertexAttribArray(pos_loc);

src/vrend_renderer.c

@@ -976,7 +976,7 @@ static struct vrend_linked_shader_program *lookup_shader_program(struct vrend_co
            return ent;
      }
   }
-  return 0;
+  return NULL;
 }
 
 static void vrend_destroy_program(struct vrend_linked_shader_program *ent)