Github 581 - Upgrade doctest

 * Upgrade doctest to version 2.4.6 to allow Arm NN to build with
   glibc 2.34

Signed-off-by: Jan Eilers <jan.eilers@arm.com>
Change-Id: Iff2ef286ba5ad0e0ec0f54f510253a2ec4b464d3
diff --git a/src/backends/backendsCommon/test/JsonPrinterTestImpl.cpp b/src/backends/backendsCommon/test/JsonPrinterTestImpl.cpp
index c4c9f7f..a1128cf 100644
--- a/src/backends/backendsCommon/test/JsonPrinterTestImpl.cpp
+++ b/src/backends/backendsCommon/test/JsonPrinterTestImpl.cpp
@@ -68,7 +68,7 @@
             }
             catch (std::invalid_argument const&)
             {
-                FAIL("Could not convert measurements to double: " + numberString);
+                FAIL(("Could not convert measurements to double: " + numberString));
             }
 
             numberString.clear();
@@ -83,7 +83,7 @@
             }
             catch (std::invalid_argument const&)
             {
-                FAIL("Could not convert measurements to double: " + numberString);
+                FAIL(("Could not convert measurements to double: " + numberString));
             }
             numberString.clear();
         }