tracing/histograms: Return an error if we fail to add histogram to hist_vars list

stable inclusion
from stable-v5.10.188
commit 43e786aa51b80e5856c8f1c4ad46a5784364ebe6
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8KYFP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=43e786aa51b80e5856c8f1c4ad46a5784364ebe6

--------------------------------

commit 4b8b3905 upstream.

Commit 6018b585 ("tracing/histograms: Add histograms to hist_vars if
they have referenced variables") added a check to fail histogram creation
if save_hist_vars() failed to add histogram to hist_vars list. But the
commit failed to set ret to failed return code before jumping to
unregister histogram, fix it.

Link: https://lore.kernel.org/linux-trace-kernel/20230714203341.51396-1-mkhalfella@purestorage.com



Cc: stable@vger.kernel.org
Fixes: 6018b585 ("tracing/histograms: Add histograms to hist_vars if they have referenced variables")
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>