treewide: fix shell errors during dump stage
Fixes following issues:
bash: -c: line 1: `echo
1686820180<LINUX_VERMAGIC> | /staging_dir/host/bin/mkhash md5 | cut -b1-8'
bash: -c: line 1: `echo
1686820180<LINUX_VERMAGIC> | /staging_dir/host/bin/mkhash md5 | sed -E 's/(.{8})(.{4})(.{4})(.{4})(.{10})../\1-\2-\3-\4-\500/''
bash: -c: line 1: syntax error near unexpected token `|'
bash: line 1: *1024*1024: syntax error: operand expected (error token is "*1024*1024")
bash: line 1: (64 + ): syntax error: operand expected (error token is ")")
expr: syntax error: missing argument after '+'
Signed-off-by: Petr Štetiar <ynezz@true.cz>