...even if GetColumnCount()*MINLAY > USHRT_MAX could ever be true, in which case
it will now cap m_nWidth == USHRT_MAX.

(The original code didn't have the cast of GetColumnCount() to sal_Int32, then
7e7c8a51 "#80552#: bug fixes for progress" added
a---presumably misplaced---C-style cast to the check (but not the assignment),
presumably to silence some signed-vs-unsigned warning.)

Change-Id: I2403ee3c5e8fe35ae2a7a7b7da9081a7fb7b59b1
Reviewed-on: https://gerrit.libreoffice.org/48654Tested-by: Stephan Bergmann <sbergman@redhat.com>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>