Some rewriting in SfxViewShell::ExecPrint_Impl
Some rewriting in SfxViewShell::ExecPrint_Impl

* add comments
* reorganise if statement
* use of the IsAPI function
* prevent segfault (NULL pointer dereferencing)

Change-Id: I79b010e676ea5efc23903d6c63e04175871d1258

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core