pvattest/tools: fix endianness in tools

`od` in contrast to `xxd` uses the system endianness for displying the
hexdump by default which leads to invalid results on little endian
systems.
Use the `--endian=big` option to fix the endianness problem.

Fixes: 3cc0b4cd ("pvattest/tools: remove xxd dependency from scripts")
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

pvattest/tools/pvattest-info

@@ -14,7 +14,7 @@ set -o pipefail
 set -o nounset
 set -e
 
-XDUMP='od -A x -t x2z -v'
+XDUMP='od -A x -t x2z -v --endian=big'
 
 usage() {
 	cat <<-EOF

pvattest/tools/pvextract-hdr

@@ -14,7 +14,7 @@ set -o pipefail
 set -o nounset
 set -e
 
-XDUMP='od -A x -t x2z -v'
+XDUMP='od -A x -t x2z -v --endian=big'
 
 def_output='sehdr.bin'
 def_skip=0x14