exclude .pc/ and patches/ dirs even when they are in a differen dir than ${S}, because of patchdir param

sometimes .pc/ and patches/ are not in ${S}, because of SRC_URI's patchdir param, eg in libstd-rs

https://static.rust-lang.org/dist/rustc-1.59.0-src.tar.xz;name=rust
file://0001-Add-400-series-syscalls-to-musl-riscv64-definitions.patch;patchdir=../../
file://0001-Update-checksums-for-modified-vendored-libc.patch;patchdir=../../

S is tmp/work/core2-64-poky-linux/libstd-rs/1.59.0-r0/rustc-1.59.0-src/library/std but patches are in tmp/work/core2-64-poky-linux/libstd-rs/1.59.0-r0/rustc-1.59.0-src/ so the SKIPPATHS exclusion doesn't work here.

We need to add some logic in bbtracer_do_patch_postfunc