ieframe/tests: Use proper helpers for iface calls

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
http://testbot.winehq.org/JobDetails.pl?Key=20435

Your paranoid android.


=== WNT4WSSP6 (32 bit intshcut) ===
intshcut.c:112: Test failed: interface {cabb0da0-da57-11cf-9974-0020afd79762} could not be queried
intshcut.c:380: Test failed: SetUrl failed, hr=0x80041001
intshcut.c:381: Test failed: SetUrl failed, hr=0x80041001
intshcut.c:383: Test failed: unexpected URL change www.winehq.org -> http://www.winehq.org (expected http://www.winehq.org/)
intshcut.c:384: Test failed: unexpected URL change ftp.winehq.org -> ftp://ftp.winehq.org (expected ftp://ftp.winehq.org/)
intshcut.c:231: Test failed: Unable to get an IPropertySetStorage, hr=0x80004002
intshcut: unhandled exception c0000005 at 00402932

=== WNT4WSSP6 (32 bit webbrowser) ===
webbrowser.c:3289: Test failed: Creating WebBrowser object failed: 80040154
webbrowser.c:3289: Test failed: Creating WebBrowser object failed: 80040154
webbrowser.c:3289: Test failed: Creating WebBrowser object failed: 80040154
webbrowser.c:3428: Test failed: Creating WebBrowser object failed: 80040154
webbrowser: unhandled exception c0000005 at 0040810F

=== W2KPROSP4 (32 bit webbrowser) ===
webbrowser.c:2596: Test failed: expected GetOverridesKeyPath
webbrowser.c:2601: Test failed: expected Invoke_SETSECURELOCKICON
webbrowser.c:2602: Test failed: expected Invoke_FILEDOWNLOAD
webbrowser.c:3015: Test failed: doc_disp == NULL
webbrowser: unhandled exception c0000005 at 00402F21