Use IncompatibleMethTypeProblem instead of MissingMethodProblem.

Author: HyukjinKwon

project/MimaExcludes.scala

@@ -350,7 +350,7 @@ object MimaExcludes {
         ProblemFilters.exclude[MissingMethodProblem]("org.apache.spark.mllib.regression.LinearRegressionWithSGD.this")
       ) ++ Seq(
         // SPARK-15250 Remove deprecated json API in DataFrameReader
-        ProblemFilters.exclude[MissingMethodProblem]("org.apache.spark.sql.DataFrameReader.json")
+        ProblemFilters.exclude[IncompatibleMethTypeProblem]("org.apache.spark.sql.DataFrameReader.json")
       ) ++ Seq(
         // SPARK-13920: MIMA checks should apply to @Experimental and @DeveloperAPI APIs
         ProblemFilters.exclude[DirectMissingMethodProblem]("org.apache.spark.Aggregator.combineCombinersByKey"),