vt: fix double-click word selection for last word on line

[emaste]

Summary

Previously when double-clicking on the last word on a line we would select from the beginning of the word to the cursor position, because we searched forward for a space character to find the end of a word. Now, use the end of the line if we do not find a space.

PR: 261553

[emaste]

sys/dev/vt/vt_buf.c

822–823

unrelated whitespace change - will commit separately (or drop)

[markj]

sys/dev/vt/vt_buf.c

830

Not really familiar with this code - should it perhaps be i - 1?

[emaste]

sys/dev/vt/vt_buf.c

830

It's one past the end of the selection - above it is set to the column where the space is found, but the space is not included, below in VTB_MARK_ROW it's vb->vb_mark_end.tp_col = vb->vb_scr_size.tp_col for the whole row.