get rid of unnecessary warning

A value of 0 for Opcode eOp produces a debug assertion that is
not in place as opcode with value does exist (ocPush, SC_OPCODE_PUSH).

Change-Id: If529cc2ecd8d4d3a5e31f084dfa72e13c9c0fe37
Reviewed-on: https://gerrit.libreoffice.org/5586Reviewed-by: Thorsten Behrens <tbehrens@suse.com>
Tested-by: Thorsten Behrens <tbehrens@suse.com>

formula/source/core/api/FormulaCompiler.cxx

@@ -488,8 +488,8 @@ uno::Sequence< sheet::FormulaOpCodeMapEntry > FormulaCompiler::OpCodeMap::create
 
 void FormulaCompiler::OpCodeMap::putOpCode( const String & rStr, const OpCode eOp )
 {
-    DBG_ASSERT( 0 < eOp && sal_uInt16(eOp) < mnSymbols, "OpCodeMap::putOpCode: OpCode out of range");
-    if (0 < eOp && sal_uInt16(eOp) < mnSymbols)
+    DBG_ASSERT( sal_uInt16(eOp) < mnSymbols, "OpCodeMap::putOpCode: OpCode out of range");
+    if (sal_uInt16(eOp) < mnSymbols)
     {
         DBG_ASSERT( (mpTable[eOp].Len() == 0) || (mpTable[eOp] == rStr) ||
             (eOp == ocCurrency) || (eOp == ocSep) || (eOp == ocArrayColSep) ||