Test for the correct exception in FilesystemUtilsTest.

--
MOS_MIGRATED_REVID=97236025
diff --git a/src/test/java/com/google/devtools/build/lib/unix/FilesystemUtilsTest.java b/src/test/java/com/google/devtools/build/lib/unix/FilesystemUtilsTest.java
index d23bbb2..aad70b2 100644
--- a/src/test/java/com/google/devtools/build/lib/unix/FilesystemUtilsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/unix/FilesystemUtilsTest.java
@@ -31,7 +31,6 @@
 
 import java.io.File;
 import java.io.FileNotFoundException;
-import java.io.IOException;
 
 /**
  * This class tests the FilesystemUtils class.
@@ -106,7 +105,7 @@
     try {
       FilesystemUtils.setWritable(foo);
       fail("Expected FilePermissionException, but wasn't thrown.");
-    } catch (IOException e) {
+    } catch (FilePermissionException e) {
       assertThat(e).hasMessage(foo + " (Operation not permitted)");
     }
   }