patch 9.1.1696: tabnr from getwininfo() for popup windows is always 0

patch 9.1.1696: tabnr from getwininfo() for popup windows is always 0

Problem:  getwininfo() has logic for getting the tabnr of a local popup
          window, but due to only breaking from the inner loop, tp is
          eventually set to NULL, so tabnr is always 0.
Solution: Break out of both loops, continue to use 0 for global popup
          windows (Sean Dewar).

closes: #18111

Signed-off-by: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>