opengles2: Batching lines/points used wrong var for summing vertex counts.

Fixed this in the vitagxm backend too, but I don't know what the state of
that code is otherwise.

Reference Issue #5061.

src/render/opengles2/SDL_render_gles2.c

@@ -1205,7 +1205,7 @@ GLES2_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *ver
                                 break;  /* can't go any further on this draw call, different blendmode copy up next. */
                             } else {
                                 finalcmd = nextcmd;  /* we can combine copy operations here. Mark this one as the furthest okay command. */
-                                count += cmd->data.draw.count;
+                                count += nextcmd->data.draw.count;
                             }
                             nextcmd = nextcmd->next;
                         }
@@ -1236,7 +1236,7 @@ GLES2_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *ver
                         break;  /* can't go any further on this draw call, different texture/blendmode copy up next. */
                     } else {
                         finalcmd = nextcmd;  /* we can combine copy operations here. Mark this one as the furthest okay command. */
-                        count += cmd->data.draw.count;
+                        count += nextcmd->data.draw.count;
                     }
                     nextcmd = nextcmd->next;
                 }

src/render/vitagxm/SDL_render_vita_gxm.c

@@ -817,7 +817,7 @@ VITA_GXM_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *
                         break;  /* can't go any further on this draw call, different texture/blendmode copy up next. */
                     } else {
                         finalcmd = nextcmd;  /* we can combine copy operations here. Mark this one as the furthest okay command. */
-                        count += cmd->data.draw.count;
+                        count += nextcmd->data.draw.count;
                     }
                     nextcmd = nextcmd->next;
                 }