scripts: in case of failed download, remove partial files

It happens from time to time that the server mis-behaves, and breaks the
connection right in the middle of nowhere, for no good reason, leaving us
with a partial file, on which the extract pass would choke.

Remove partial downloads, to fail early.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from eefacabd9e72f3d578e5dc5908026ed780f9a240)

 --- binutils/ld/emulparams/elf_i386.sh

 +++ binutils/ld/emulparams/elf_i386.sh

 @@ -13,3 +13,13 @@

  NO_SMALL_DATA=yes

  SEPARATE_GOTPLT=12

  IREL_IN_PLT=

 +

 +# In Gentoo, we install 32bit libs into /lib32 in an

 +# ABI setup with amd64/x86

 +case "$target" in

 +  x86_64*-linux*)

 +    case "$EMULATION_NAME" in

 +      *i386*) LIBPATH_SUFFIX=32  ;;

 +    esac

 +  ;;

 +esac