Remove split.cc from the bazel sources.

Change-Id: I15eb78eaccabb3c00610b3d8bfcb22a6156105df

bazel/ceres.bzl

diff --git a/bazel/ceres.bzl b/bazel/ceres.bzl
index ce170b2..8dd62c5 100644
--- a/bazel/ceres.bzl
+++ b/bazel/ceres.bzl
@@ -116,7 +116,6 @@
     "sparse_cholesky.cc",
     "sparse_matrix.cc",
     "sparse_normal_cholesky_solver.cc",
-    "split.cc",
     "stringprintf.cc",
     "subset_preconditioner.cc",
     "suitesparse.cc",