VideoTextureHelper: create QRhiTextureUploadEntry inplace


`QRhiTextureUploadEntry entry` is copied instead of moved, but we can
better creat the initializer_list in-place

Coverity-Id: 915277
Pick-to: 6.12
Change-Id: I4e77ec4a0d65dc4149ca78c9ee30304692eb69bb
Reviewed-by: Mikko Hallamaa <mikko.hallamaa@qt.io>
commite40808d9c13e8a7f640e26f6d721c85a9d2d07bb
parentba1e4681fabbd8864616417f0ab2f6d173a877fe
authorTim Blechmann <tim.blechmann@qt.io>
committerTim Blechmann <tim.blechmann@qt.io>
commit timeThu, 22 Oct 2026 06:07:06 +0000