[MINOR][SQL] Update the description of spark.sql.files.ignoreCorruptF…

…iles and spark.sql.columnNameOfCorruptRecord

### What changes were proposed in this pull request?
1. The description of `spark.sql.files.ignoreCorruptFiles` is not accurate. When the file does not exist, we will issue the error message.
```
org.apache.spark.sql.AnalysisException: Path does not exist: file:/nonexist/path;
```

2. `spark.sql.columnNameOfCorruptRecord` also affects the CSV format. The current description only mentions JSON format.

### How was this patch tested?
N/A

Author: Xiao Li <gatorsmile@gmail.com>

Closes #18184 from gatorsmile/updateMessage.

sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -345,7 +345,8 @@ object SQLConf {
     .createWithDefault(true)
 
   val COLUMN_NAME_OF_CORRUPT_RECORD = buildConf("spark.sql.columnNameOfCorruptRecord")
-    .doc("The name of internal column for storing raw/un-parsed JSON records that fail to parse.")
+    .doc("The name of internal column for storing raw/un-parsed JSON and CSV records that fail " +
+      "to parse.")
     .stringConf
     .createWithDefault("_corrupt_record")
 
@@ -535,8 +536,7 @@ object SQLConf {
 
   val IGNORE_CORRUPT_FILES = buildConf("spark.sql.files.ignoreCorruptFiles")
     .doc("Whether to ignore corrupt files. If true, the Spark jobs will continue to run when " +
-      "encountering corrupted or non-existing and contents that have been read will still be " +
-      "returned.")
+      "encountering corrupted files and the contents that have been read will still be returned.")
     .booleanConf
     .createWithDefault(false)