kmod: fix build failure in install step over dirty build dir

kmod: fix build failure in install step over dirty build dir

When building kmod-32 package for the first time (clean build_dir), it
builds and installs fine. When building for 2nd time, sometimes
(probably some race condition?) it fails to build in install step with
following error:

  for tool in insmod lsmod rmmod depmod modprobe modinfo; do \
  	ln -s kmod /tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/$tool; \
  done
  ln: failed to create symbolic link '/tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/insmod': File exists
  ln: failed to create symbolic link '/tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/lsmod': File exists
  ln: failed to create symbolic link '/tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/rmmod': File exists
  ln: failed to create symbolic link '/tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/depmod': File exists
  ln: failed to create symbolic link '/tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/modprobe': File exists
  ln: failed to create symbolic link '/tmp/build_dir/target-aarch64_cortex-a73+neon-vfpv4_musl/kmod-32/ipkg-install/usr/bin/modinfo': File exists

Lets fix it by backporting upstream fix.

Fixes: #27171
Link: https://lore.kernel.org/r/20240306145804.135709-1-lucas.de.marchi@gmail.com
Upstream-Status: Backport [https://github.com/kmod-project/kmod/commit/c5054b215089f9e3cdc9602232649c2b5b1de743]
Signed-off-by: Petr Štetiar <ynezz@true.cz>