Description: tracing/trigger: Fix to return error if failed to alloc snapshot
References:
Notes:
 carnil> Introduced in 0bbe7f719985 ("tracing: Fix the race between registering
 carnil> 'snapshot' event trigger and triggering 'snapshot' operation"). Vulnerable
 carnil> versions: 4.4.220 4.9.220 4.14.177 4.19.117 5.4.34 5.5.19 5.6.6 5.7-rc2.
Bugs:
upstream: released (6.8-rc3) [0958b33ef5a04ed91f61cef4760ac412080c4e08]
6.8-upstream-stable: N/A "Fixed before branching point"
6.7-upstream-stable: released (6.7.6) [4b001ef14baab16b553a002cb9979e31b8fc0c6b]
6.6-upstream-stable: released (6.6.18) [6022c065c9ec465d84cebff8f480db083e4ee06b]
6.1-upstream-stable: released (6.1.79) [36be97e9eb535fe3008a5cb040b1e56f29f2e398]
5.10-upstream-stable: released (5.10.210) [56cfbe60710772916a5ba092c99542332b48e870]
4.19-upstream-stable: released (4.19.307) [bcf4a115a5068f3331fafb8c176c1af0da3d8b19]
sid: released (6.7.7-1)
6.1-bookworm-security: released (6.1.82-1)
5.10-bullseye-security: needed
4.19-buster-security: needed