templates: use span for inline elements

Instead of using div and making it an inline elment with css use span
which already is a inline element.

kallithea/public/css/style.css

@@ -3183,11 +3183,6 b' input.perm_filter {'
     font-size: 16px;
 }
 
-.compare-revision-selector > div {
-    display: inline-block;
-    margin-right: 8px;
-}
-
 table.code-difftable {
     border-collapse: collapse;
     border-radius: 0px !important;

kallithea/templates/compare/compare_diff.html

@@ -28,18 +28,18 b''
         <div id="body" class="panel-heading">
             <div class="compare-revision-selector">
                 ## divs are "inline-block" and cannot have whitespace between them.
-                <div>
+                <span>
                     ${h.hidden('compare_org')}
-                </div><div>
+                </span><span>
                     <i class="icon-right"></i>
-                </div><div>
+                </span><span>
                     ${h.hidden('compare_other')}
-                </div><div>
+                </span><span>
                     %if not c.compare_home:
                         <a class="btn btn-default btn-sm" href="${c.swap_url}"><i class="icon-arrows-cw"></i> ${_('Swap')}</a>
                     %endif
                     <div id="compare_revs" class="btn btn-default btn-sm"><i class="icon-git-compare"></i> ${_('Compare Revisions')}</div>
-                </div>
+                </span>
             </div>
         </div>