[SPARK-14496][SQL] fix some javadoc typos

## What changes were proposed in this pull request?

Minor issues. Found 2 typos while browsing the code.

## How was this patch tested?
None.

Author: bomeng <bmeng@us.ibm.com>

Closes #12264 from bomeng/SPARK-14496.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/StringUtils.scala

@@ -57,7 +57,7 @@ object StringUtils {
    * This utility can be used for filtering pattern in the "Like" of "Show Tables / Functions" DDL
    * @param names the names list to be filtered
    * @param pattern the filter pattern, only '*' and '|' are allowed as wildcards, others will
-   *                follows regular expression convention, case insensitive match and white spaces
+   *                follow regular expression convention, case insensitive match and white spaces
    *                on both ends will be ignored
    * @return the filtered names list in order
    */

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkSqlParser.scala

@@ -475,7 +475,7 @@ class SparkSqlAstBuilder extends AstBuilder {
    *   ALTER VIEW view ADD [IF NOT EXISTS] PARTITION spec
    * }}}
    *
-   * ALTER VIEW ... DROP PARTITION ... is not supported because the concept of partitioning
+   * ALTER VIEW ... ADD PARTITION ... is not supported because the concept of partitioning
    * is associated with physical tables
    */
   override def visitAddTablePartition(