fix format

Author: xudong963

datafusion/optimizer/src/push_down_filter.rs

@@ -2308,7 +2308,7 @@ mod tests {
             plan,
             @r"
         Projection: test.a, test1.d
-          Cross Join:
+          Cross Join: 
             Projection: test.a, test.b, test.c
               TableScan: test, full_filters=[test.a = Int32(1)]
             Projection: test1.d, test1.e, test1.f
@@ -2338,7 +2338,7 @@ mod tests {
             plan,
             @r"
         Projection: test.a, test1.a
-          Cross Join:
+          Cross Join: 
             Projection: test.a, test.b, test.c
               TableScan: test, full_filters=[test.a = Int32(1)]
             Projection: test1.a, test1.b, test1.c