[PATCH] covoar: Fix NULL check of wrong variable

[Alex White]

In Explanations::writeNotFound() there were two NULL checks of the
`fileName` variable where only one is needed. The second check has been
changed to a NULL check of `notFoundFile` to match the original intent.

Closes #4377
---
 tester/covoar/Explanations.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tester/covoar/Explanations.cc b/tester/covoar/Explanations.cc
index 7b0f95a..12bd809 100644
--- a/tester/covoar/Explanations.cc
+++ b/tester/covoar/Explanations.cc
@@ -140,10 +140,10 @@ done:
       return;
 
     notFoundFile = fopen( fileName, "w" );
-    if (!fileName) {
+    if (notFoundFile == nullptr) {
       std::ostringstream what;
       what << "Unable to open " << fileName
-           << "out of sync at the explanation";
+           << " out of sync at the explanation";
       throw rld::error( what, "Explanations::writeNotFound" );
     }
 
-- 
2.27.0