coverity#1430057 silence Argument cannot be negative

Change-Id: I58bf1a204393ea95c85f51cf9ef3387db1565a4e
Reviewed-on: https://gerrit.libreoffice.org/51558Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

lingucomponent/source/hyphenator/hyphen/hyphenimp.cxx

@@ -284,7 +284,7 @@ Reference< XHyphenatedWord > SAL_CALL Hyphenator::hyphenate( const OUString& aWo
     }
 
     // if we have a hyphenation dictionary matching this locale
-    if (k != -1)
+    if (k >= 0)
     {
         int nHyphenationPos = -1;
         int nHyphenationPosAlt = -1;