Revert "mkinitramfs: check if initramfs has a shell"

This reverts commit 9c823ad2.  It did
not solve the problem it was intended to, because it used "$DESTDIR"
in the destination argument to copy_exec and would therefore copy to
/var/tmp/<something> inside the initramfs.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

mkinitramfs

@@ -379,11 +379,6 @@ if [ -e "${CONFDIR}/DSDT.aml" ]; then
 	copy_file DSDT "${CONFDIR}/DSDT.aml"
 fi
 
-# Make sure there is a final sh in initramfs
-if [ ! -e "${DESTDIR}/bin/sh" ]; then
-	copy_exec /bin/sh "${DESTDIR}/bin/"
-fi
-
 [ "${verbose}" = y ] && echo "Building cpio ${outfile} initramfs"
 
 if [ -s "${__TMPEARLYCPIO}" ]; then