pkg/bpf: remove unnecessary PerfEvent.Read return value
pkg/bpf: remove unnecessary PerfEvent.Read return value

PerfEvent.Read always returns nil, so the error return value can be
omitted.

Signed-off-by: Tobias Klauser <9249c549618448e4c699e8032ba6c7f0d7fd4b7f@distanz.ch>

tklauser/cilium,gumpt/cilium,tgraf/cilium,scanf/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,gumpt/cilium,scanf/cilium,eloycoto/cilium,michi-covalent/cilium,eloycoto/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,scanf/cilium,scanf/cilium,tklauser/cilium,eloycoto/cilium,tgraf/cilium,tgraf/cilium,eloycoto/cilium,cilium/cilium,tgraf/cilium,gumpt/cilium,michi-covalent/cilium,eloycoto/cilium,gumpt/cilium,tklauser/cilium,eloycoto/cilium,gumpt/cilium,gumpt/cilium,gumpt/cilium,cilium-team/cilium,scanf/cilium,eloycoto/cilium,tklauser/cilium,scanf/cilium,cilium/cilium,cilium-team/cilium,scanf/cilium,michi-covalent/cilium,tgraf/cilium