perf: valgrid errors with pprof enabled

[prataprc]

When we compile bin/perf with pprof feature and run it via valgrind there seem to be memory-leaks. Is that normal ?

$ cargo build --release --bin perf --features=perf,pprof
$ valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes ~/.cargo/target/release/perf --loads 1000000 --gets 100000

Results in:

==79781== LEAK SUMMARY:
==79781==    definitely lost: 327,104 bytes in 2 blocks
==79781==    indirectly lost: 17,563,648 bytes in 4,096 blocks
==79781==      possibly lost: 0 bytes in 0 blocks
==79781==    still reachable: 24,606,855 bytes in 12,003 blocks
==79781==         suppressed: 0 bytes in 0 blocks