meta: toolchain-shar-relocate.sh: Filter out post-relocate-setup script

The toolchain-shar-extract.sh script updates the SDK relocation paths in
post-relocate-setup.sh, so avoid doing this twice. This is generally not
a problem, unless the SDK path is a subset of the SDK relocation path, in
which case the resulting path is substituted twice. To trigger the issue,
  $ ./tmp/deploy/sdk/poky-glibc-x86_64-core-image-base-core2-64-qemux86-64-toolchain-3.2+snapshot.sh -y -d /home/oe/.local/opt/poky/3.2+snapshot
which generates relocation path
  /home/oe/.local/home/oe/.local/opt/poky/3.2+snapshot
instead of
  /home/oe/.local/opt/poky/3.2+snapshot

Fixes: 93ec145f ("toolchain-shar-extract: Add post-relocate scripts")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Joshua Watt <JPEWhacker@gmail.com>
Cc: Krzysztof Zawadzki <krzysztof.zawadzki@nokia.com>
Cc: Randy Witt <randy.e.witt@linux.intel.com>
Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>