perf bpf: Fix a typo in bpf_counter_cgroup.c

perf bpf: Fix a typo in bpf_counter_cgroup.c

This patch fixes a spelling typo in error message.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211225005558.503935-1-standby24x7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>