qemu testing: extract_od_binary.sh: support huge files (and broken od)

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

qemu_multiarch_testing/extract_od_binary.sh

@@ -3,4 +3,4 @@
 # Converts textual result of "od -tx1 <FILE"
 # back into a binary FILE
 
-grep -a '^[0-7][0-7][0-7][0-7][0-7][0-7][0-7] [0-9a-f][0-9a-f] [0-9a-f][0-9a-f] [0-9a-f][0-9a-f] [0-9a-f][0-9a-f]' | busybox hexdump -R
+grep -a '^[0-7][0-7][0-7][0-7][0-7][0-7][0-7][0-7]* [0-9a-f][0-9a-f] [0-9a-f][0-9a-f] [0-9a-f][0-9a-f] [0-9a-f][0-9a-f]' | busybox hexdump -R