Consistently acquire solar mutex in all CreateSalInstance variants

...where all but the variants for Android and --enable-headless already did so
(and curiously the DestroySalInstance variants for Android and --enable-headless
already contained code to release the solar mutex).  See the thread at
<http://lists.freedesktop.org/archives/libreoffice/2012-December/042535.html>
"--headless broken with --enable-headless" for further details.

Change-Id: I01be2e237e203a151ea8b1f3adfbcb3e63247cd7

vcl/android/androidinst.cxx

@@ -151,6 +151,7 @@ SalInstance *CreateSalInstance()
     fprintf (stderr, "Android: CreateSalInstance!\n");
     AndroidSalInstance* pInstance = new AndroidSalInstance( new SalYieldMutex() );
     new AndroidSalData( pInstance );
+    pInstance->AcquireYieldMutex(1);
     return pInstance;
 }
 

vcl/headless/headlessinst.cxx

@@ -121,6 +121,7 @@ SalInstance *CreateSalInstance()
 {
     HeadlessSalInstance* pInstance = new HeadlessSalInstance( new SalYieldMutex() );
     new HeadlessSalData( pInstance );
+    pInstance->AcquireYieldMutex(1);
     return pInstance;
 }