macOS: Remove un-needed auto-release pools in QCocoaInputContext

These functions do not push much pressure on memory to warrant separate
pool, and are otherwise called as part of the normal runloop which has
its own pool.

Change-Id: If84a899edc4e8cefbf58ecb55d46848ccd69b33b
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

src/plugins/platforms/cocoa/qcocoainputcontext.mm

@@ -116,7 +116,6 @@ void QCocoaInputContext::commit()
     if (!view)
         return;
 
-    QMacAutoReleasePool pool;
     [view unmarkText];
 
     [view.inputContext discardMarkedText];
@@ -147,7 +146,6 @@ void QCocoaInputContext::reset()
     if (!view)
         return;
 
-    QMacAutoReleasePool pool;
     if (NSTextInputContext *ctxt = [NSTextInputContext currentInputContext]) {
         [ctxt discardMarkedText];
         [view unmarkText];