Remove unused member from Totals

At one point it was inserted there as the simplest way to smuggle
around an extra return value for specific errors in executing
tests. Since then, the error has been changed to be handled
differently, and the member became unused.

src/catch2/catch_session.cpp

@@ -330,7 +330,7 @@ namespace Catch {
             // Note that on unices only the lower 8 bits are usually used, clamping
             // the return value to 255 prevents false negative when some multiple
             // of 256 tests has failed
-            return (std::min) (MaxExitCode, (std::max) (totals.error, static_cast<int>(totals.assertions.failed)));
+            return (std::min) (MaxExitCode, static_cast<int>(totals.assertions.failed));
         }
 #if !defined(CATCH_CONFIG_DISABLE_EXCEPTIONS)
         catch( std::exception& ex ) {

src/catch2/catch_totals.hpp

@@ -33,7 +33,6 @@ namespace Catch {
 
         Totals delta( Totals const& prevTotals ) const;
 
-        int error = 0;
         Counts assertions;
         Counts testCases;
     };