Minor fixes

Based on William Rucklidge's review, including
a nasty bug in parameter block removal.

Change-Id: I3a692e589f600ff560ecae9fa85bb0b76063d403
diff --git a/internal/ceres/solver.cc b/internal/ceres/solver.cc
index 6d38535..b1bd2d8 100644
--- a/internal/ceres/solver.cc
+++ b/internal/ceres/solver.cc
@@ -311,7 +311,7 @@
 
     StringAppendF(&report, "\n");
 
-    StringAppendF(&report,   "%45s    %21s\n", "Given",  "Used");
+    StringAppendF(&report, "%45s    %21s\n", "Given",  "Used");
     StringAppendF(&report, "Threads:            % 25d% 25d\n",
                   num_threads_given, num_threads_used);