perf evsel: display dmesg command of showing a hardcoded path

In non-FHS compliant distros like NixOS, nothing resides in `/bin`
and `/usr/bin`. Instead dynamically symlinked into
`/run/current-system/sw/bin/`, the executable resides in `/nix/store`.

With this patch,`/bin` prefix from the dmesg command in the error
message is stripped.

Link: https://github.com/NixOS/nixpkgs/pull/258027



Signed-off-by: Masum Reza <masumrezarock100@gmail.com>
Cc: Yunseong Kim <yskelg@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20240922112619.149429-1-masumrezarock100@gmail.com


Signed-off-by: Namhyung Kim <namhyung@kernel.org>