perf report: Switch data file correctly in TUI

perf report: Switch data file correctly in TUI

The 's' key is to switch to a new data file and load the data in the
same window.  The switch_data_file() will show a popup menu to select
which data file user wants and update the 'input_name' global variable.

But in the cmd_report(), it didn't update the data.path using the new
'input_name' and keep usng the old file.  This is fairly an old bug and
I assume people don't use this feature much. :)

Link: https://lore.kernel.org/r/20250211060745.294289-1-namhyung@kernel.org
Closes: https://lore.kernel.org/linux-perf-users/89e678bc-f0af-4929-a8a6-a2666f1294a4@linaro.org
Fixes: f5fc14124c5cefdd ("perf tools: Add data object to handle perf data file")
Reported-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>