PEL: Save invalid host PELs to a file

To aid in debug of when the host sends down an invalid PEL, save the PEL
to the file 'badPEL' in the PEL repo path.  This only saves a single one
at a time to keep things simple.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I3b630433712d63cadd971aa87a02f76a9a366849
diff --git a/test/openpower-pels/pel_manager_test.cpp b/test/openpower-pels/pel_manager_test.cpp
index 530dfd5..00427c2 100644
--- a/test/openpower-pels/pel_manager_test.cpp
+++ b/test/openpower-pels/pel_manager_test.cpp
@@ -176,6 +176,10 @@
     EXPECT_EQ(logger.ad["SRC"], (*invalidPEL.primarySRC())->asciiString());
     EXPECT_EQ(logger.ad["PEL_SIZE"], std::to_string(data.size()));
 
+    // Check that the bad PEL data was saved to a file.
+    auto badPELData = readPELFile(getPELRepoPath() / "badPEL");
+    EXPECT_EQ(*badPELData, data);
+
     fs::remove_all(pelFilename.parent_path());
 }